Arsene Wenger defended his decision to rest Robin van Persie after Arsenal's bid to reach the Champions League knockout stage was put on hold following a 0-0 draw with Marseille.
Van Persie has been in blistering form for Arsenal recently, scoring a hat-trick in last week's stunning 5-3 victory at Chelsea and inspiring a Gunners revival which has seen them march up the Premier League table.
However Wenger chose to leave the flying Dutchman on the bench for Tuesday's visit of Group F rivals Marseille, in a game where three points would have seen the Gunners qualify for the last 16 with two games to spare.
Yet Wenger's gamble in handing South Korean international Park Ju-Young his first Champions League start in place of van Persie failed to pay off as a toothless Arsenal attack failed to trouble Marseille.
Although Park ultimately made way for van Persie with just under half an hour remaining, by then the pattern of a disappointing game had been established and Arsenal were unable to test their Ligue 1 opponents.
Van Persie did have one shot on goal after being released by Tomas Rosicky, but the striker's cheeky 77th-minute attempted chip was comfortably gathered by Marseille keeper Steve Mandanda.
Although the result left Arsenal on top of Group F, leading Marseille by one point, the Gunners cannot afford to take anything for granted in their final two group games, at home to Borussia Dortmund and away to Olympiakos.
Wenger however was adamant that he had been right to rest van Persie.
"He was tired. He was fatigued. That's why I did that," Wenger said. "You know we're playing 50 games in a year -- he cannot play 50 games.
"He had one great chance when he tried to chip the keeper but you just have to accept it."
Wenger also rejected suggestions that Arsenal were becoming over-reliant on van Persie.
"You cannot just say that one player would make all the difference. I felt it was a game where we were not physically the sharpest.
"But I still feel that in the first half we had opportunities to kill the game. You have to give credit to Marseille, they defended very well, and we were not sharp enough to take advantage of the chances we created.
"Overall we know that in the final third we can do better."
Wenger agreed with the observation that Park, signed in the summer from French side Monaco, would take a while to make the step up to Champions League football.
Park had scored a fine goal for Arsenal during last week's League Cup win over Bolton, but found the going hard on Tuesday.
All too often promising Arsenal attacks broke down when the ball reached the South Korean, with the 26-year-old often needing one touch too many or miscontrolling altogether.
"He did very well for us last week," Wenger said. "But tonight you could see he lacked a bit of the pace of the game. He's not played enough games."
Wenger also believes Arsenal had suffered a hangover following their heroics at Stamford Bridge three days earlier, when they had twice come from behind to overcome Chelsea.
"I think it took a toll on us emotionally more than physically," he said. "It's difficult to be on a high three days later.
"But we still had the opportunities in the first half through (Aaron) Ramsey and Gervinho. In a game like that you still expect to take those chances.
"Up front we lacked a bit of precision. We weren't that clinical."