The 20-year-old has not started since the opening day win over Leicester City, with Romelu Lukakuthe preferred option.
"I don't think there is trust from the manager to the player that he can do it on a regular basis. That is why he is only coming into the team now and again.
"He is only 20 years old and he probably needs a little more time, but I think this season is a big season for him. Come the end of the season he then has to make the decision.
"He's got to start playing regularly."