I thought initially it was because he might be feeling the pressure?
Last few games, results have hardly improved
Otherwise it's a cowardly thing to do, having a go at a young lad in public, if it wasn't working for whatever reason take him off, tell the press he felt a twinge, and sort it out in the dressing room and leave it there.
If he took that action against a youngster he should have butted Bacuna as he came off the pitch!!

To easy to lay into a youngster and he's lost a lot of the support and good will from fans in my view with his comments