England left-back Luke Shaw says he will continue to support the team whether he plays or not.
Gareth Southgate decided against playing a left-back in the 1-0 win over Croatia on Sunday, instead starting right-back Trippier at the position.
"We found out the day before the game. We had a meeting in the morning and he (Southgate) obviously named the team," said the Manchester United defender.
"Of course, I think, not just mine, but anyone has initial thoughts when they're not playing in a game that everyone wants to play in – it is obviously disappointing.
"But even if you're not playing, I think we've still got a role in the team to train well, train properly and get the lads ready for a very big game and do whatever is necessary to play my part in getting them ready for that.
"I was obviously disappointed, but Gareth has 11 players he needs to pick and all I can do is train well, train hard and see what Gareth does in the next game.
"But that's the only thing I can do, keep smiling, keep enjoying it and do whatever I can to help the team, whether I am playing or not."