The 21-year-old is currently on his second loan spell at Doncaster Rovers in League One and has enjoyed a strong start there once again.
Louis van Gaal chose De Gea, Lindegaard and Amos as his three senior goalkeepers which meant Johnstone’s game would have been limited to the U21s again, so he decided a loan move was in his best interest but does want to fulfil his boyhood dream of having a United career.
“Old Trafford is obviously where I want to be,” he said.
“It is difficult. Obviously [David] De Gea is not much older than me.
“I’ve been there since I was ten years old and sometimes you have to come away and learn your trade, to go back and push.
“It’s every boy’s dream to play for Manchester United and I signed a new contract not long ago,” he added.
“But who knows? We’ll see what happens.”
Unfortunately for Johnstone, he is only two years younger than De Gea and unless the Spaniard leaves United then the No.1 spot at Old Trafford won’t be available any time soon.
That being said, Lindegaard is likely to leave at the end of this season so he could be elevated into the senior squad but if first-team football is what Johnstone craves, then it’s hard to see him ever getting that at United while De Gea is still there.
It all depends how patient Johnstone is and whether he is willing to fight for the No.1 spot because he may soon decide a move elsewhere is the better decision for his career prospects.