The midfielder scored the winner against Bournemouth on Saturday.
"It's so important for him, the first one for the team," he said.
"He has to know he has to compete with Bernardo [Silva] and [Raheem] Sterling, he has to be ready. If he is positive and thinks 'okay my time is going to come' then his time is going to come because there are a lot of games.
"I have no doubts about his quality, his mentality is aggressive but he has to understand where he is: a team that got 100 points and every single game fights and runs and plays, and the people in front are one of the most important players of last season in Leroy, the best player in the league in Bernardo and an incredible player in Raheem."