Onana has been with Man Utd for more than 2 seasons and should have realized that he is not a good fit for Man Utd. To save his career, going elsewhere is a way out, but who wants it? There is no one because Man Utd wants a high price, or another way is to ask him to be loaned out because of course with the arrival of a new goalkeeper and currently Amorim trusts Bayindir more, so Onana is only the third choice. I really feel that Onana's career will really stagnate if he stays at Man Utd for too long.
Loaning out Onana with no fees will be probably Best Thing Man United could have done to him looking to his current form and performance, morever sending him to
TRABZONSPORTrabzonspor makes a bit sense. Andre Onana were one of best keeper in recent time after deGea, but somehow the criticm from the fans and the constant comparison with De Gea didn't let him gain his confidence back just like he delivers previous season and become best. But now I think this loan period he will spend in Turkey will have be a great chance to make a comeback, as the Turkish league is less superior than the Premier League in term of team potential and he will get a decent chance to rebuild. So If he works hard and proves himself by delivering strong performances then he can return back to premier league or several other top league and played for different sides, but if he fails to take advantage of that loan spell then we can say that his career can stagnate.