Lonsdale famously earned trials at United by knocking on the front door of Sir Alex Ferguson's house.
The midfielder is recovering from an ankle injury while he waits for a decision from Saunders.
He recalled to the Daily Mail: "I played five reserve games in all, one alongside Darron Gibson, who said he couldn't believe I was only 18, and I trained with the likes of Darren Fletcher, Danny Welbeck and Tom Cleverley.
"Warren (Joyce) said how well I was doing, and I thought I had every chance. Then one day after training he called me into a room. I knew it was decision time and the nerves kicked in again. He explained they had been waiting for certain players to go out on loan and free up some space, but they hadn't. They were younger players on contract and it meant he couldn't offer me anything. I was devastated. It was hard to take."