Arsène Wenger has defended his decision to go into Saturday's encounter against Tottenham Hotspur with top scorer Thierry Henry on the substitutes' bench.
And the 1-1 draw with Spurs leaves the Gunners' chances of securing fourth spot in the Premiership out of their hands. But Wenger is adamant the personnel were not the problem.
"I don't believe that it was a team selection problem," he said, "it was a physical problem."
"We play every three days and people maybe don't realise that but you know you can sometimes suffer.
"It's difficult to imagine how much tension is in the Champions League games and you know you could have a flat half [of football], no matter who started the game."
"It is a real battle at that level, where everybody goes one hundred percent for it. You have to recover as well and of course people will criticise because Thierry Henry didn't play."
Wenger also pointed out that Villarreal rested ten players ahead of the Semi Final second leg in Spain on Tuesday and praised the 'character' shown by his troops in the last-ever North London derby to be played at Highbury.
"Now we play against Villarreal on Tuesday night and you know how many players they will rest tonight - ten," he said.
"We keep going and have shown character at the moment where it was very difficult for us.
"I am very proud of the character we have shown, the only regret I have is that we bombarded many long balls in the last ten minutes when maybe we should have worked to our strengths and combined around the box."Copyright 2015 The Arsenal Football Club plc. Permission to use quotations from this article is granted subject to appropriate credit being given to www.arsenal.com as the source