He doesnt need to, he will be on the starting team no matter what. We could already guess arsenal's next season starting line up based on, if giroud hasnt been sold yet then he would be starter along with sanchez and mahrez as winger and ramsey and ozil as their midfielder , coaquelin as defensive midfielder
all the players of his age would be ambitious young beramain in big club and a big salary
to play in a big club, apart from salaries, advertising bids will also flow in him
with the increasing popularity, due to play in a big club, would often go to interviewed journalists and sections of the media coverage
It is a good move if he decided to join arsenal rather than some other team which hasnt even really 'confirmed' yet wether he will have his spots in the first squad or not. So its all good for him if he actually come down to a deal with arsenal, there is no better team currently to start his career as a top football player rather than any other club out there that will only put him on the bench