Wingers don't just need to beat a man, they need to deliver quality into the box or hit a good shot at goal once they have done that. Thomas rarely does either of those things.
If he is a winger , then why when he is in a position to put the ball in the box , which he has been on many occasions , does he not deliver ? . If you watch him closely , when he is on the ball he rarely lifts his head & that could be the reason , I dont know ,I am not a coach but from a personal point of view , I played on the wing for many years & when I was in a position to cross the ball the first thing I would do is to look up & see who I could pick out , its a basic skill , his decision making in the final third is shocking , hopefully that can be worked on but football is no different to any other that 90% of the game is played with your brain & he seems to find this part of the game difficult . I stress that this only my opinion & sincerely hope he proves me wrong & goes on to be a world beater .