The right-back was hurt in the closing stages of the 1-1 draw with Young Boys and was not available for the trip to East Anglia.
Ralf has stuck with the full-backs on duty against Crystal Palace last time out in the Premier League, with Alex Telles starting and Luke Shaw on the bench.
"I think everybody did well, including the two full-backs, against Palace," said Rangnick. "Offensively, they put a lot of effort into it and they were always dangerous, putting crosses into the centre of the box. I was very pleased with both of them against Palace.