Lees is set to be out until the new year, after damaging his hamstring last week.
The former Leeds United centre-back had been the only mainstay in Wednesday’s squad this season, and Wallace had been impressed by his teammate’s performances.
“It’s a big blow," Wallace admitted. "Tom has played really well this season and has played pretty much every game. He’s a good professional, but I don’t think Michael Turner is that far away and Sam [Hutchinson] played well on Sunday.”
Wednesday have one of the biggest squads in the Championship, but it will be a challenge for them to cope without Lees.
Carlos Carvalhal has built his team around the strength of the 25-year-old’s defenisve qualities so far.
Lees has helped Wednesday have an impressive defensive record, and it will be up to other members of the squad to step-up to prove they can cope without him.
The Owls are one of the Championship’s form sides at the moment, and they have lost just two of their last 16 matches in all competitions.
At the moment Carvalhal’s team are level on points with the play-off places, and they will hope to continue to climb up the standings, over the Christmas period.