Dean Henderson has blasted Manchester United's actions as 'criminal' in a sensational interview.
The goalkeeper, on a season-long loan at Nottingham Forest from Old Trafford, revealed he was left 'fuming' after false promises from the club.
Henderson told Talksport that United promised he would usurp David de Gea as No 1, but then made him a reserve and kept him on the bench.
He said: 'To be quite honest with you, it's probably been the toughest 12 months of my career. It's been tough, it's been hard and I'm so happy I've come out the other end of it now.
'The conversation I had, coming out of the Euros squad (with England), was that you're coming back here (to United) to be the number one goalkeeper. I got Covid, then unfortunately no one followed through with anything they told me.
'It's frustrating as well, because I turned so many good loans down last summer for that reason and they wouldn't let me go. To sit there and waste 12 months is criminal, really, at my age. I was fuming.'
Experienced stopper De Gea, 31, made 46 appearances in all competitions last season, with Henderson just given three outings, once each in the FA Cup, League Cup and Champions League.
And Henderson also admitted he refused to speak to or train under new United manager Erik ten Hag in a bid to force through a move to the newly promoted side.
He added: 'No. I didn't want him to see me in training. Because I knew that he probably wanted to keep me. So I told the hierarchy that I need to play football, I don't want to be here and play second fiddle.'
The season before last, which saw United finish second in the Premier League under Ole Gunnar Solskjaer, Henderson played 26 times in all competitions, compared to De Gea's 36, and saw the England star end the season as first choice.
One-cap international Henderson slowly worked his way up to the top level, with loans at Stockport in the National League North, Grimsby in League Two, Shrewsbury in League One and Sheffield United in the Championship and Premier League.
The Whitehaven-born star will return to Old Trafford at the end of the season, given Forest could not negotiate an option to buy in his loan contract.
De Gea, who was one of United's best players last season, will be backed up by Tom Heaton this campaign.