Odd one this. On one hand I have sympathy for him as he came into the team, on the back of a good season at Charlton, was playing well for England under 20/21s and then he's largely ignored by Koeman and Allardyce.
On the other hand, he has really not shown any indication that he deserves a starting place, seems to constantly have a cloud over him in respect of agitating for a move.
At 20/21 he should be working hard to nail down a place, especially given the transition into a new set up and obvious willingness to invest in youth. The sensible thing for him is to work hard and grab a place in the team. There's no better stage than the EPL to show your ability.
If he is prepared to stay, we have to give him some chances to impress without expecting him to be an instant world beater as a 10 minute sub. If he's not happy to fight for his place then we should get rid as he's not what we need.