Young demands improvement
Wasps will aim to put what an "unacceptable" performance behind them against European Rugby Champions Cup play-off opponents Stade Francais.
The seventh-placed Aviva Premiership and Top 14 finishers clash in the first of two legs at Adams Park.
At stake is the 20th and final qualifying spot for next season's inaugural tournament, which succeeds the Heineken Cup.
Wasps ended their Premiership campaign by suffering a crushing 74-13 defeat against title-chasing Northampton last Saturday, and director Dai Young said: "Last weekend's performance was unacceptable.
"We were all incredibly disappointed, especially with the way we lacked fight when we went behind.
"That performance certainly won't be brushed under the carpet, but the detailed post-mortem must wait until after these two games.
"I think people will understand that we are not in a position where we can dwell on it too long. These two play-off games are huge for the club, the players and our supporters.
"There has been a lot of hurt around the camp, so it may be the ideal time to go into this game.
"We've all looked at where we need to improve, and I have been very pleased with the response players have shown in training. The intensity has been good, and now we need to translate that on to the pitch on Sunday."
Young welcomes back a number of players for Stade's visit as Wasps look to take charge ahead of next Saturday's return encounter in Paris.
Captain Chris Bell and wing Tom Varndell are the only backs who remain following the Northampton game, while six switches up-front see starts for Matt Mullan, Carlo Festuccia, Phil Swainson, Joe Launchbury, Ashley Johnson and former Stade player James Haskell.
"Defence normally gives an indication of the mindset of a team, and that mindset wasn't right the last couple of games (against Northampton and Newcastle), given the way we leaked tries," Young added.
"Certainly, up until those two games, our defence and attitude had been excellent, so we need to recapture that hunger and desire and produce the work-rate and attitude in defence to give ourselves a good chance. I am sure we will do that on Sunday."