Almost all players decline at some stage of their career. It is only natural that, as time takes its toll, the body can no longer handle the physical demands of playing soccer at the highest level. That is the natural method of decline, but some players decline when their bodies are still at their peak. This can be down to an array of factors; ranging from a loss of confidence to a personal event which may have taken place in the players life.
It is worth noting that the title says 'soccer stars', and as such, the list is restricted to just that, those who were and have been stars of the game. There are literally thousands of soccer players on the decline at any given time, but only those who were once regarded as being fine players qualify here. Every player on this list has played top flight, Champions League and international soccer.
Lastly, some players, such as Samuel Eto'o or Alessandro Del Piero, do not feature because although they may still be declining as players, they have ultimately already declined from being the top players they once were a number of years ago. The 15 men on this list are on the cusp of decline and are either only just or only recently began their downward spiral. Here are the top 15 soccer stars on the decline:
15 Nemanja Vidic
Nemanja Vidic arrived at Manchester United in 2006 as a tall but skinny center-half who struggled with the physicality of the Premier League. He left Manchester United in 2014 as a powerful and dominant defender, who had won five Premier League titles and one Champions League, and was regarded as an all-time Manchester United legend. Big, strong and technically gifted, Vidic was a titan at the back at United, and virtually unbeatable in the air. Despite his brilliance, he was often plagued by injury troubles, and now aged 33, United probably sold him at the right time. At Inter, he conceded a penalty and was sent off, and spent much of the season on the bench.
What is there left to say of Xavi? Many have said that he has epitomized Barcelona, and La Masia, over the last decade. Incredible vision and passing ability have made him one of the greatest midfielders of his generation, but Xavi's true genius lies in his ability to find space, receive the ball, and move it on. In this respect, there is probably no one better in the world. Sadly, after almost 800 games for Barca, Xavi has moved on. His decline was obvious after he spent much of last season as back-up to Ivan Rakitic. Xavi will spend next season with Qatari club Al Sadd, where his abilities are likely to continue to decline in a considerably weaker league.
Brazilian attacking midfielder Diego has had an unusual career, with his form often rising and falling dramatically; he looks a genius at times and totally invisible at others. As such, it's difficult to truly call when Diego is declining or just in a poor spell of form. I think now is the time though. He is 30 years old and last summer he headed to Fenerbahce, rather than one of Europe's top leagues. Diego has played for Santos, Porto, Werder Bremen, Juventus, Wolfsburg, Atletico Madrid and now Fenerbahce, with his best spells coming with the two German sides, he has also played 33 times for Brazil.
12 Vincent Kompany
Vincent Kompany was named the Premier League Player of the Season in 2010/11, and has thrice been named in the Team of the Year; some indication of what a good player he has been for Manchester City. Arriving before the club became awash with money, Kompany has survived and thrived despite the multi-million pound arrivals at the Etihad. The Belgian hasn't even hit 30 yet but there is reason to believe he is already on the decline. The 2013/14 season wasn't his finest, yet most believed it was a blip, however, he did little to show that was the case in 2014/15. Next season is a big one for Kompany, and I'm not sure he's got what it takes anymore.
11 Rafael van der Vaart
Rafael van der Vaart is a player of outstanding natural ability. His skill, passing and vision are all superb, and he has all the attributes to be able to play well in to his 30s. At 32, van der Vaart is on a steep decline. Hailed as the next Johan Cruyff when he emerged from Ajax's famed academy, soon joining Hamburg, then Real Madrid, then Tottenham, returning to Hamburg and this summer, Real Betis. Essentially, van der Vaart has spent the last three seasons at a relegation threatened Bundesliga side, before joining a Spanish side who spent last season in the second division. It is some indication that van der Vaart is no longer a top player, and at 32, it can be very difficult to stop the rot.
10 Iker Casillas
Iker Casillas has been one of the greatest goalkeepers of all time at Real Madrid, and deserves to be remembered as such, yet his departure from the club came as little surprise to most, and that is because Casillas is no longer the keeper he once was. Aged 34, most goalkeepers are still at their peak, yet for Casillas, he has struggled to be at his consistent best since 2012, and joined Porto last week. With over 150 caps for Spain, he is only the third man in history to captain a team to World Cup, European Championship and Champions League success, which is some achievement. Casillas will hope to re-ignite his career in Portugal, but it's unlikely he'll ever reach the heights of his best days at Real.
9 Wesley Sneijder
It is easy to forget just how highly regarded Wesley Sneijder was at one point. In 2010, he was incredible, being the key man in both Inter Milan's legendary treble season and Holland's World Cup team which reached the final. He was named in the World Cup Dream Team, as well as being man of the match in the Champions League final, named the best midfielder in Europe and came fourth in the Ballon d'Or vote. At that time, it was basically a universal view that letting Sneijder go was a huge mistake by Real Madrid. Yet even the following season Sneijder struggled to reach his true best. He joined Galatasaray in 2013 and whilst impressing in Turkey, it is not the level a player of his caliber should be plying his trade in, and at 31, he's unlikely to get a move back to one of Europe's top teams.
8 Steven Gerrard
Some would say that Steven Gerrard has already declined, but despite not making as many appearances for Liverpool last season, Brendan Rodgers tended to save him for the big games, and he will still be a very difficult player to replace at Anfield. Gerrard's mobility most certainly has gone, although his range of passing and ability from a dead ball situation most certainly has not. If L.A. Galaxy build a team around Gerrard, ensuring that the Englishman is not loft exposed, then he still has the ability to tear apart the MLS. The 2014 World Cup was the first real indication that Gerrard is not the player he once was. He struggled in every game and the time was right for him to leave the Premier League.
7 Michael Essien
Michael Essien has had a truly horrible time with injuries for the last seven years now; in only one of the last eight seasons has he made over 30 league appearances, having made less than 15 in six of them. They are telling statistics, and no player could return from such absence without their confidence and ability to have taken a knock, and Essien is no different. A decade ago, Essien was one of the most highly regarded midfielders in the world, he justified that view at Chelsea, but his first injury struck after just three years at the club. After two difficult years with AC Milan, Essien joined Panathinaikos this summer, some fall from grace, and a sad indication of the Ghanaian's decline.
6 Mario Gomez
Mario Gomez was always a tricky player to assess. One of very few remaining 'poachers' in the game, Gomez scored goals for fun but rarely seemed to offer a lot else to the team. This much is obvious because despite an incredible goal scoring record with Bayern Munich, the Bavarian club were happy to let him move to Fiorentina in 2013 for just over $20 million. With such a reliance on goals, it is always a worry when they dry up for a player of Gomez's ilk. He has had two nasty injuries in Florence, scoring only seven goals in 29 league games in the Serie A. Gomez is now 30 and has not been a regular member of the Germany team for three years now.
Brazilian left-back Maxwell has had a very impressive career, despite never truly being in the 'world class' category. With Ajax, Inter Milan, Barcelona and PSG, Maxwell has won an incredible 10 league titles, 13 domestic trophies and three European titles. Despite those impressive stats, Maxwell has been capped only 10 times by his country and has rarely been regarded as one of the world's best left-backs. Given that speed was an important part of his game, the now aged 33 Maxwell faces a tough task maintaining his form of the last three years. There were signs towards the back end of last season that Maxwell was slowing down, and PSG may well be looking elsewhere next summer.
4 Rodrigo Palacio
Unlike a lot of promising South American players who swap South America for Europe in their late teens or early 20s, Rodrigo Palacio did not make the move until the age of 27, having already been an Argentine international for four years. He joined Genoa in 2009 where he partnered up with compatriot Hernan Crespo. After three years, Palacio headed to Inter Milan. The last three years have been some of the club's worst in history, languishing in midtable and despite Palacio's decent goal scoring record, he showed a significant drop in form last season. Having scored 17 league goals in the previous season, he managed only eight last season. As a player heavily reliant on pace, the 33-year-old's best days appear to be well behind him.
3 Patrice Evra
Patrice Evra has followed a rather similar career path to that of Nemanja Vidic. Both joined Manchester United in January 2006, both struggled with the physicality of the Premier League at first before putting in the hard yards, winning numerous trophies and leaving Old Trafford as club legends. They also both headed to Italy, but whilst Vidic joined strugglers Inter Milan, Evra joined the dominant side in Serie A currently, Juventus. Evra was famed for his rock solid defensive work and ability to break forward at speed; now aged 34, the second of those is becoming a real struggle for the Frenchman. He played only 20 league games last season and is no longer one of the best left-backs in the world.
2 Philippe Mexes
Another Frenchman and another Serie A player, Philippe Mexes. Mexes made a name for himself in France with Auxerre, where he was called up to a strong national team, and soon headed to Roma. At Roma, he cemented his reputation as one of Europe's leading center-backs, and consequently headed to AC Milan. It has not been quite such a happy story since leaving the Italian capital, and Mexes has since became a laboriously slow and error-prone defender who is often targeted by opposing teams. He too played only 20 league games last season in a miserable campaign and appears to be on a very steep decline.
1 Robin van Persie
It is amazing just how quickly van Persie has gone from one of the world's leading marksmen to a Premier League cast-off heading to Turkey. He was the Premier League Golden Boot winner in 2011/12 and the 2012/13 seasons where he scored 56 league goals with Arsenal and Manchester United in two seasons. After a less impressive 2013/14 campaign, hopes were high when van Persie impressed at the World Cup, under soon-to-be United manager Louis van Gaal. However, even van Gaal couldn't turn things around, as the Dutchman scored 10 goals in 29 games. The Netherlands' all-time leading scorer, he is only 31, but none of Europe's top teams appeared interested in him this summer, and he instead signed for Fenerbahce.