After an emotional promo backstage on Raw, Rey Mysterio was not on this week's show. There's a good reason and Mysterio updated his fans as to why.

There's no reason to put the same WWE Superstars each and every week but when you're in the starting phases of an emotional and dramatic storyline like it appears Rey Mysterio is in, it's a bit odd to have your performer deliver one of the more emotional moments of his career and then not use him the following week. But, for Rey Mysterio, there was a good reason he was not at Raw this past Monday.

As he shared when he posted a photo of himself in a medical gown, Mysterio was not at WWE TV this week because he was in Columbia to undergo another round of stem stell treatments.

In a series of photos on his Instagram page, Mysterio walked fans through what it's like to get these treatments, which he credits for helping him with his knee issues. His knee problems have been a big focus of his career and injury history as of late. It was a major reason his return to WWE took as long as it did. He's really moving around much better as a result of the treatments.

Mysterio is just one of many stars to have undergone similar stem cell work (Kurt Angle, Kevin Nash, Ken Shamrock, and Ryback) but he's potentially the one active wrestler still trying to go strong and work a somewhat regular wrestling schedule.

What This Means

WWE is happy to let Rey take time every once and a while to get the treatments he needs because it means having Mysterio around a bit longer. It's also leading to a program between Rey and his son Dominick.

Speculation is that Dominick will eventually debut as “Principe Mysterio” which translates to “Prince Mysterio.” Rey will have a big hand in all of that.

Next: [Rumor] Paul Heyman Handpicks Raw Superstar He's Trying To Get Over