I honestly don't think coming on as a 20 minute sub is all that difficult.People need to remember Alvarez didn't have friggin extended break this year, we need to be careful to manage his minute or he will get burnout. Also he playing for World Cup and seems have very important role in there so no break for him during World Cup either.
We need him to be able to play for full season and not getting burnout at the end of season.