There are several changes to the side that lost to the Warriors last Sunday.
Mark Van Gisbergen returns to fullback after missing the last game due to a wedding in New Zealand. His return means Josh Lewsey will shift back to wing. An ankle injury to Tom Voyce means John Rudd will start at No.11.
Voyce picked up the injury during the Warriors game and is only expected to miss this game.
Stuart Abbott also makes a welcome return after picking up an ankle injury during the England v Barbarians game in December. Abbott will start alongside Fraser Waters at centre with Mark Denney moving onto the bench.
In the front row, Will Green comes in for Tim Payne while in the backrow
Jonny O'Connor starts at openside with Paul Volley on the bench. Gatland said, 'Friday night is a must win for Wasps. A loss could destroy any hopes we have of progressing in the Heineken Cup'.
'Everyone at the club was very disappointed at the loss last Sunday. After going two months without losing means we take these things personally.
However, we've regrouped, had a look at where we went wrong and are ready to bounce back.
'The Warriors are a very strong side and deserved their win. Our pride has been severely dented. Friday night is a challenge of immense proportions'.
Wasps: M Van Gisbergen; J Lewsey, F Waters, S Abbott, J Rudd; A King, R Howley; C Dowd, T Leota, W Green, S Shaw, M Purdy, J Worsley, J O'Connor, L Dallaglio (capt)
Replacements: P Greening, T Payne, P Volley, G Skivington, P Richards, A Erinle, M Denney
Referee: Joel Dume (France)