he should start re-schooling himself as a 10 or hang up his boots.
a winger that slow simply doesn't make sense.
speed isn't just an issue when it's used. anyone who's played football knows that it functions as an essential bargaining piece when taking on a defender. if you're faster than the attacker, he'll be more afraid of the duel because losing means he can't catch you. he'll back up and keep space between you, which works in your favor.
if he knows he can catch you, he won't be afraid of the duel, he'll be in your face, shutting your space down, which makes it a lot harder.
playing as a slow winger in today's football where 95% of fullbacks are rapid is useless. you're out of the game before you begin.