Ziggler was a guest on Miz TV, along with Hall of Famer Shawn Michaels. At the end of the show, Goldberg showed up and signed the contract, before Michaels executed his Sweet Chin Music finisher on Ziggler to close out Raw.
So why did WWE choose Ziggler as the opponent for the 2018 Hall of Fame inductee? According to Brad Shepard of Oh, You Didn't Know (h/t Ringside News), it's because of Ziggler's ability to "make Goldberg look good."
This comes as no surprise, given Goldberg's mistake-filled match against The Undertaker at Super ShowDown. The two superstars botched a series of moves throughout the match. On one instance, Goldberg droppped The Phenom on top of him when trying to execute a Tombstone Piledriver. Not only that, but Goldberg suffered a concussion after crashing headfirst into the ring post.
Undertaker defeated Goldberg in a matter of minutes, and some wondered if that would be it for the latter's in-ring career. But Goldberg expressed his desire to "erase the memory" from the Super ShowDown match, and that was a clear indicator that he would be back in the ring in short time.
Interestingly, Dave Meltzer of Wrestling Observer Radio suggested that Raw Executive Director Paul Heyman will use Goldberg in a Bruno Sammartino-like role. That is, Goldberg will wrestle a handful of times a year - since he's still a big draw to the wrestling world.
What This Means
All indications suggest that SummerSlam won't mark the final match of Goldberg's career. He remains in good shape, and his matches tend to only last a few short minutes. Goldberg is capable of wrestling several more matches a year in the foreseeable future, so long as the opponents are chosen wisely - and there's good reason to believe Ziggler will do just fine this Sunday.