ESPN is reporting that the Red Devils are facing competition from Tottenham Hotspur and West Ham United for the highly-rated West Brom goalkeeper in the summer.
The same article states that Manchester United are looking at Johnstone as a potential replacement for David De Gea if the Spain international leaves Old Trafford this summer.
According to the same story, Ole Gunnar Solskjaer has earmarked Johnstone as his preferred choice to replace De Gea ahead of the 2021-22 Premier League season.
The report goes on to add that the 28-year-old wouldn’t be willing to settle for a back-up role at Manchester United if the Red Devils did re-sign Johnstone.