Johnstone has joined the Brewers on loan until the end of the season.Denny Johnstone is a Scottish footballer who plays for English club Birmingham City. A striker, he began his career with Celtic, but left in 2014 without making a first-team appearance.
He spent time on loan with Conference club Macclesfield Town and League Two club Cheltenham Town in 2014–15. He has represented Scotland from under-16 to under-19 level.
He will stay with the Brewers until the end of the season but Birmingham can recall the striker after 28 days.