I don't know how true it is but he played in the league a long time, overlapping with Utley for several years. I'm sure he knows a lot of guys still playing in the league too. I doubt his opinion is coming out of nowhere. Is it accurate? No idea, but his opinion is informed.
First, Sheffield has a long reputation as a douche. Not who I'd call credible.
Second, I've followed Utley for a long time and this is not the narrative up til now. But the pitchforks are out and lazy people like Sheffield want to pile on.
Third, here's Charlie Manuel on Utley (doesn't sound like a guy who can't take it):
“That’s the way he plays. The first time I ever seen him was in Rochester playing triple-A baseball, that’s the first game I’ve even seen him and he hit a catcher, and the catcher was big, and he threw Chase up in the air about three or four feet over his back, and he landed and it hurt him. And I said to him after the game I said “way to go” and he looked at me and he said “I don’t know, Charlie.”
And in Utley’s career, Utley’s been hit a lot at second. He’s also a guy when he catches a ball, he stays there … he stays in too long sometimes. And I seen times like Lasting Milledge in Warshington one night spiked him real high, basically just jumped up on his knee, and he slid high and he cut him, and they were showing a replay of it and they had a recording in Warshington’s clubhouse at the time, and Milledge is sitting there bragging about doing it, saying he meant to do it …
And then in Cincinnati he got cut (physically), and he would never tell me. He wouldn’t even say something to a trainer unless another player, Jimmy Rollins or somebody, would say something to him. And that’s who he is …
I knew he did not slide to hurt Tejada, but he had the intention to take him out on the double play. He slid late, but he definitely did not mean to hurt him in no way.”