So as you know GP so well, why has he brought so many players to the club during his tenure that he now apparently doesn't fancy? Tau (recalled from loan), Moder, Wellbeck, Zeqiri. All signed up on his watch. None of whom are getting a look-in. (You could probably add Karbownik to the list)
Then you get the consistent under-performers. Trossard. What is he doing on the training ground that is so impressive? Because he sure as hell ain't doing it on matchday.
As for Trossard I would imagine he is showing on the training ground that he is a better player than the alternatives. He is also occasionally showing it in games, currently being the number one assist maker in the team. I think he is far too inconsistent but I also think that Trossard on a good day is pretty much as good as it gets from this squad. He was excellent during the recent win/draw streak and there's really not many similar players to him in the squad or even the U23 squad.
As for the signed players, some are quite obviously for the future. Karbo is a 19 year old signed from a League One level league, Zeqiri a young player from a worse league than that. I understand that everyone wants to see the new guys but Premier League is a huge step up. Moder is also signed from the poor Polish league and in his case he also got absolutely massive competition. They are signed up for the future.
Tau... I think the club took a chance. "He's been ok in Belgium and we need another striker, lets get him home and see what we can do". Connolly, Welbeck and Ali J were injured at that point and the club was playing games like twice a day and as we've noticed the club is not going to pay for an established striker. Probably they've now seen enough of Tau to think "not good enough". Happens in every club.
Welbeck played 30% of all minutes this season and I'm not sure how much more than that people expect really.