Over the last 3 or 4 seasons he's probably averaged only about 1,500 minutes on the pitch (circa 16 full matches) a season or maybe 30% of the matches.
Erik Lamela - Stats 18/19 | Transfermarkt
Crudely we need 3 Lamela's to fill one place in the team for a season - and if every player was like that we'd need 66 players to have a full team and a back up team (as we have now) to put that into perspective.
Puts his injuries into perspective.
And in whatever other job would you receive a full wage if you were not available 70% of the time ?
Problem is he is probably not saleable - who else would want his wages given his lack of playing time - but if there is a way to sell him we should have done it yesterday and get someone half decent who is fit most of the time