The forward was missing from the Whites squad for Sunday's draw with Leicester City at Elland Road, head coach Marcelo Bielsa revealing Gelhardt had not felt quite right since last Tuesday's EFL Trophy outing at Salford City.
"Gelhardt in the game on Tuesday felt some discomfort that in itself is not an injury, but he didn’t feel at 100 per cent for a high level game," said Bielsa.
According to the FA's website for the England youth squads, Fulham's Jay Stansfield has been called up to replace Gelhardt during the current international break.
Last month Gelhardt was promoted to the Under 21s, joining Whites team-mate Charlie Cresswell. This time round Cody Drameh has been moved up a squad and he and Cresswell will be hoping for involvement in Thursday night's game against Czech Republic at Turf Moor, before they travel to Georgia next Tuesday.
Andy Edwards' Under 20s, for whom Leeds pair Sam Greenwood and Lewis Bate are likely to feature, have just one fixture this month. They travel to the Dr. Magalhaes Pessoa Stadium in Leiria for an international match against Portugal on Thursday.