While Johnstone is yet to be offered a contract, we take a look at what Johnstone could offer to the Whites - if signed. So - here is everything you need to know about the Whites' potential new addition: Key details Age: 20 Nationality: England Position: Goalkeeper His career so far Max, brother of West Brom goalkeeper Sam, was nurtured in Fleetwood Town's academy before catching the eye of Manchester United. While brother Sam was sent on loan to Aston Villa, Max was let go by the Red Devils, though was quickly snapped up by Sunderland. Last season, Johnstone battled Anthony Patterson and Max Stryjek for the number one jersey in the Black Cats' under-23s set-up. However, after marking his debut year on Wearside with eight Premier League 2 appearances, Johnstone was let go. What has been said about him in the past? Sunderland’s academy manager Paul Reid described Johnstone as a "good size and character" and also believed he had potential. “Max was a player who was flagged up after he came in during the previous season," Reid said, speaking last year. “He was someone we wanted to take another look at and Mark Prudhoe was very complimentary of him after he came in last year. “His attitude has been brilliant since he came in and it has been nice to see him improve over the weeks. “He is a good size and character, and he is someone we think can develop.” What will he bring to Leeds? Johnstone evidently has good ability with clubs like Man United and Sunderland already on his CV. Given he is just 20 years old, Johnstone still has time to show his worth and fulfill his undoubted potential. That, of course, comes down to coaching, and Leeds have already shown they are more than capable of developing youngsters into first-team players. Johnstone may have joined at the right time, too, with a lot of work going into strengthening the youth academy given the acquisitions of Liam McCarron and Rafa Mujica.