Midfielder faces six weeks absence while Kevin and Kieffer are doubts for Cardiff
Luke has not featured this season after undergoing surgery on a damaged nerve in his leg but was back in the squad at the start of the month and had played for the U23s.
An ankle injury sustained when he blocked a shot in training has been revealed as ruptured ligaments though.
“Luke will be glad when this season is over,” Town boss Mick McCarthy told the Club website.
“He will be out for six weeks or so from when he did it. It’s a blow for him and for us.
“Looking at Saturday, Kevin Bru and Kieffer Moore are our main concerns. Kevin took a knock in training on Tuesday and Kieffer has a groin strain.
“Tom Lawrence and Didz [David McGoldrick] both missed training at the start of the week but they trained today.
“Emyr [Huws] can’t play against Cardiff because of his loan but he’s not fit anyway. He has a tight hamstring.”