I'm glad he's upset, they all should be
last year MP was at his best when Diangana was in the side as he had someone else on the same wavelength to partner up with. When Diangana was injured that was when MP looked less effective and during games you'd see the frustration coming out via snapping at opposition players / increased diving and complaining to the ref. This side of his character isn't new, during his time at West Brom he's always been hyper competitive and reacted when things don't work out
Diangana is struggling this year and there's no one else stepping up, MP started the season well but like everyone else the longer this season goes on the more he looks beaten by the downward momentum around the club but I don't think you can point to many games where he hasn't at least given 100%. Add to that I don't imagine he has anything in common with Allardyce when it comes to football and the reports that Krov is available for other clubs in the transfer window its not hard to imagine he may not be happy about multiple things at the moment. Add in the fact that players who aren't pulling their weight are reportedly on over double his current wage and I think he's being quite restrained!
Given the way this season has panned out the only thing I regret about the fact we cant attend games is the fact that for many of us we probably wont have the opportunity to watch Pereira live in a West Brom shirt again. He's a cut above the rest of this team, if we could have a few more players of his quality and fight we might be in a better place