The point is that no guarantee it will happen. Sure, he can work hard or whatever, but will he get enough minutes to get a spot in a national team or something else? Assuming he will gradually earn the starting spot means that either the players got injured or they got a drop-off in quality. Not sure if he's comfortable with that. A rotation player is necessary for a UCL run anyway, but from articles that we read on social media, he doesn't seem like the player who is content in that position. His situation reminds me of Elliot tbh.