Manchester United

Onana, 27, has found it difficult to impress for the 20-time English champions since arriving from Inter Milan during the summer transfer window.

The Cameroon international has conceded 14 times in his five Champions League appearances this season, and he was arguably at fault for all three of Galatasaray's goals in Wednesday's clash in Turkey.

Onana has also shipped 16 goals in the Premier League this term, but he has also managed to keep five clean sheets in the competition, and Ten Hag said on Friday that the recent arrival is the second-best goalkeeper in the league, according to the statistics.

The Man United head coach insisted that "no-one is undroppable" when asked whether there was a chance that the Cameroonian could lose his role as the number one if he continues to make mistakes.

"Of course not, no-one is undroppable. That is also clear. We believe and we have a strong belief that he will help us win trophies," Ten Hag told reporters.

The Dutchman also said that he would not accept mistakes from his goalkeeper if he was contributing in other areas, with Onana known for his ability on the ball.

"No, you don't accept [it], because he has the potential, he has the abilities to be solid in all the facets, all the elements of football. Yeah, he gives you also something extra. So definitely, in and out of possession," he added.

Meanwhile, Ten Hag also said that the dressing room is behind Onana when questioned on why none of the players on the field consoled the goalkeeper after the final whistle of the game with Galatasaray.

"No (the players are not losing faith in him). But in this dressing room this will not happen. This dressing room is together," he said.

"Yeah, football is a game of mistakes and everyone can make mistakes but then the team has to [apply a] bandage. This team has to cover that and so we will operate."

Onana has only kept one clean sheet in the Champions League this season, but he has produced shutouts in his last three Premier League games with Fulham, Luton Town and Everton.

Ten Hag also revealed that talks were taking place over Onana's participation in the Africa Cup of Nations next month, telling reporters: "So when they call him, he has to go. But we are in talks."

Altay Bayindir, who also arrived over the summer, is the number two at Old Trafford, while Tom Heaton is currently the number three at Old Trafford.