It has been reported that West Brom, who will play in the Championship next season after getting relegated from the Premier League, are interested in securing the services of the 25-year-old, who spent the 2017-18 campaign on loan at Aston Villa.
Good signing for West Bromwich Albion?
Johnstone is a very good goalkeeper who proved himself in the Championship last season, as the United-owned man did tremendously well for Villa last season.
The 25-year-old was one of the best goalkeepers in the division, and he would be a brilliant signing for West Brom, especially for £5m.
With David de Gea the clear number one at United, it is hard to see Johnstone having a long-term future at Old Trafford, and it would make sense for him to move to West Brom on a permanent deal.