#5 The Undertaker vs Sting finally takes place

Another Hall of Famer who suffered an injury with brought his wrestling career to an end was Sting, who suffered a neck injury in a match against Seth Rollins. That was Sting's fourth match in WWE back in 2015.
Most fans had given up hope of him ever returning to the ring, but Sting revealed recently that he could be up for one last match in WWE. But, his condition was that it would only be against The Undertaker:
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“If there was a Taker situation at WrestleMania, I would listen to that phone call. I could get in condition and I could pull it off." With Undertaker facing AJ Styles at WrestleMania, there's no possibility of Sting vs Undertaker happening at The Show of Shows. But, it could be a blessing, in a way, as a match of this magnitude has to happen in front of a loud and vociferous crowd.
Perhaps this could happen later this year at SummerSlam or Survivor Series in 2020?