Wallace is set to be joined by Lifeimi Mafi in the Munster squad after he completed his comeback from a shoulder operation.
It comes as some relief for team manager Shaun Payne who looks set to be without Ian Dowling, Felix Jones and Denis Fogarty for the majority of the season.
Payne said: "We're well used to dealing with these situations.
"This is professional sport, professional rugby, and these things unfortunately happen every
"We're particularly lucky this year in that we have a very competitive squad. In past seasons we had a first and a second team, maybe even a third team.
"This year we have a much tighter squad in that most of the squad are in there for selection, realistically pushing for places. We're well covered with the 38 we have."