Benjamin Sesko is going to be United's out and out striker, the manager is basically just integrating him into the team slowly, though i am not sure if that is necessary, as he could have been unleashed from the beginning.
That said, i don't think Sesko would even solve United's problems, i know they made other signings, like Cunha and Mbuemo, but the team doesn't still look like they are ready to compete. There is also a lot of pressure on the manager, his record at the club is terrible, to put it nicely and if things don't change, he could be sacked early this season.
Sesko had preseason with the team and has come off the bench in the last two games; I understand Amorim does not want to rush him in and put too much pressure on him, but if he does not start in the next game after starting in the league cup tonight, it wouldn't be wrong to say Amorim isn't as tactical as we all thought.
He's a talented manager, but I believe he's not ready for this level of football.