Alejandro Garnacho produced a man of the match performance to help Manchester United escape FA Cup embarrassment at the hands of Leicester City - but Roy Keane still doesn't trust the forward to start games.

The Foxes were one goal up at the break, causing Amorim to turn to his bench for inspiration. One man introduced, Garnacho, took the initiative throughout the second half and helped tee up another substitute, Joshua Zirkzee, for the equaliser. Harry Maguire would later score a stoppage-time winner.

The Argentine was handed the FA Cup man of the match award for his Man United heroics by ITV's Lee Dixon and on punditry duty at full-time Keane gave his honest verdict.

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He said: "I think you can trust him when he comes off the bench, I’m not sure it suits him when he starts. When he comes off the bench and they take more gambles, they stretch, that’s when he comes into his own.

"They put Leicester on the back foot. They got tired, lost a bit of physicality, and that’s what Garnacho does. You want to put defenders on the back foot. First-half they were playing sideways, playing sideways, but then they tested them and got their reward.

"When you’re defending as a team, a whole team, when teams are playing in front of you its easy. We (Keane and Ian Wright) could still play now. It’s when they start stretching you, running you back towards your own goal, that’s when you’re really tested and Leicester came up short. They couldn’t deal with it."

Since Amorim joined the club in November, Garnacho's future has been called into question. First it was because of the manager's decision, then because of the financial situation at Old Trafford, though the new manager has consistently put across the idea that the winger must change to suit his specific tactical style with inverted wingers if he is to last.

As the 20-year-old was in and out of the team last month, Amorim said: "That is clear, he has talent. He needs to learn to play a little bit in a different position. He needs to play better inside.

"He improved a lot in the recovering position, when he doesn't have the ball, but, doing that, sometimes he's not in the right place to make transitions, like he was in the past, because I prefer to defend and then build up with all the team to make the final third.

"So he's finding the best way to play in this system. He's improving, during training."

Analysing Zirkzee's equaliser, Keane added: "How simple is this? Very easy, very effective. Not complicated. One-v-one - you want wide players at Man United to go at players - test them.

"Garnacho and subs made a difference, played a lot more direct, forward passes - what they should do more of, they’re a better team - but they rode their luck."