Arsene Wenger maintains Arsenal cannot use the absence of injured captain Cesc Fabregas as an excuse for failure in Tuesday night's crunch Champions League clash with Porto at Emirates Stadium.
The influential Spain international suffered a recurrence of a hamstring problem during the 3-1 Barclays Premier League victory over Burnley on Saturday, limping off after he had fired the Gunners ahead. However, Wenger insists his side have the quality to nevertheless secure their place in the quarter-finals by overturning a 2-1 deficit from the first leg.
"Cesc has a hamstring problem and we could not even take a gamble with him," said Wenger.
"I was hoping he would recover after the Burnley game because we were cautious with him.
"We don't know how long he will be out. He is having a scan today and we are convinced it will only be a small time, and he has a small chance of getting back for next weekend against Hull, but to play him again [Tuesday] would mean significant damage."
Wenger, though, maintained: "Ideally we wanted him to be there, but we want to qualify and the absence of Cesc is no excuse at all.
"We have enough players and a strong enough squad to get round that and have enough chances to qualify."
Fabregas spent several weeks on the sidelines earlier this season because of a similar problem, yet remains Arsenal's leading scorer this season with 17 goals.
Wenger feels this latest fitness set-back is not about player burnout.
He said: "I cannot fault Spain, they only played him in one half [against France]. Cesc has given a lot recently. It is a re-occurrence in the same hamstring so we have to find out why it creates some problems."