He's treating Cavani like an 18-year old kid breaking into the first team.
Cavani played 2 games to start the season, scored 2 goals. Then gets injured Aug 30th, comes back Oct 27th. Meanwhile Icardi scores goals and he deserves to play, he's in better form right now. But since Cavani came he played 150 minutes or so in 7 games. 80 of those came in one game, others he comes in for 10 minutes even when they're leading by 3 goals. Last league game he subbed him in in injury time for 3 minutes. During the international break Cavani scored 2 goals for Uruguay.
It's made worse by his pressers. He keeps saying he's 'sad' for Cavani, he doesn't have much playing time to give him. Tonight they're playing an absolutely meaningless game at home vs Galatasaray, ideal opportunity to play him full 90' to give him confidence and score a goal or two without pressure, but he starts 8 regulars, he's playing 2 left backs, Cavani on the bench and he says 'if possible I'll try to give him some minutes'. Cavani needs 5 more goals to reach 200 for the club btw.
At this point there's no doubt he's doing it intentionally. Even Cappello didn't treat Del Piero like this. Just the way he talks about him is so demeaning and off-putting, just an awful awful man manager.