#4 Seth Rollins
Back when John Cena was a mainstay in WWE, he got into a feud with Seth Rollins. At one point during the feud, Rollins ended up breaking Cena's nose following a misplaced kick on the 16-time World Champion. Rollins received tons of flak from fans for the spot, and WWE Hall of Famer Bret 'The Hitman' Hart was among the ones who weren't happy with him.
"He [Rollins] knees him the face so hard, and so recklessly, and so dangerously. He could easily kill somebody with a knee like that to the face. It's a testimony to John Cena. A, he finished the match and B, that he didn't get a shotgun and shoot Seth Rollins when he came through the curtain."
Seth Rollins is currently one of the biggest names in WWE
This wasn't the only time Seth Rollins received criticism for being unsafe in the ring. A spot during the Universal title match between him and Finn Balor at SummerSlam 2016 was responsible for the latter getting injured and being forced to vacate his title. WWE Hall of Famer Sting was injured during his WWE World Heavyweight title match against Rollins at Night of Champions 2015, following which his career came to an end.