Sesko has a lot of time to show the club what he gat. He isn't that strong and fit to be a starter because he needs time to understand the team play pattern properly before he can exploit the league. I believe that Amorim knows what he is doing to prevent further damage to the team performance.
Has the coach or the player complained about not being fit to start or play till full time? Sesko is a new player I understand that the manager is not starting him because of the strategy his team is playing but since he is not getting the best result for the United team is it not better he tries starting Sesko to see if there will be difference in the team's performance the coach doesn't know what he is doing nobody should praise him again because he is gradually killing the team.