Man Utd keeper Johnstone enjoying Walsall loan
The 20-year-old has only conceded two goals in his five matches since joining the promotion-chasing Saddlers and is desperate to help them reach the Championship.
"Against Sheffield United was the first goal I conceded," he told MUTV. "I wasn't happy about it as I don't like conceding and the way it happened against Scunthorpe was frustrating too.
"But I look at my performance myself and don't think I could have done much about the goals that have been scored against me. It's great experience for me. Last year I was at Scunthorpe at a different end of the table but this year at Walsall I'm at the top end. It's different with different pressures but I'm enjoying it.
"There are two games left and we'll work hard to win them. It'd be great to get into the play-offs but we have got to take things one game at a time."