meaning of this sentence

Posted in Translation

Zanzibar FC Premium_small (Xain) 23 March 2019, 14:10
hello, sorry but too much slang for me, i dont understand the meaning of this sentence :

%{player} has certainly been at it for a long time, but you wouldn't know that by looking at his progression as a player. He's definitely been spinning his wheels, because he hasn't lied up to his potential at all.