if only the coaching staff will give him enough playing time, he can give more help the team to win.
It won't happen. Instead of giving him enough playing time, why not give that playing time instead to a caliber player?
He's fit in the supporting role, not as a part of the main cast. He can be a valuable backup.
Anothe reason why he is given limited playing time is, it was the health recommendation after being in a major injury.