Arsene Wenger admits that it was "a gamble" to leave Robin van Persie out of Arsenal's starting line-up against Marseille in the Champions League.
Striker Van Persie, 28, appeared in the second half as the Gunners were held to a 0-0 draw at Emirates Stadium.
Arsenal manager Wenger said: "It was a gamble that you can say didn't come off but he was very tired after the game on Saturday [against Chelsea].
"You know we're playing 50 games in a year - he cannot play 50 games."
Van Persie came on in the 62nd minute and came close to scoring when he was released by a perfect through pass from Tomas Rosicky, but he failed in his attempt to loft the ball over goalkeeper Steve Mandanda, who caught it comfortably.
"He had a chance and, if he scored, it would have been perfect," said Wenger.
Van Persie was rested three days after scoring a hat-trick in the Gunners' 5-3 victory at Chelsea to take his tally to 28 goals in his last 27 league games for the club.
Wenger admitted the thriller at Stamford Bridge may have left several of his players feeling drained.
"Emotionally more than physically maybe [it took it out of us]," he said. "Marseille were physically impressive. We lacked a bit of sharpness.
"It is difficult to be on a high three days later but we still had the opportunities.
"(Aaron) Ramsey in the first half had two great chances and Gervinho had a great chance. In a game like that you expect to take one of those chances."
Arsenal winger Theo Walcott added: "Saturday did take a lot out of us but we know what to expect in the Champions League.
"They're a very strong team, we found it quite tough out there as well. But like I said before we were very solid at the back."
Despite the stalemate, Arsenal remain top of the group, one point clear of Marseille with two games to play.
Discussing the performance, Wenger said: "We defended very well, tried very hard but we lacked some quality in the final third.
"You have to give credit to Marseille, they defended very well and stopped us from playing.
"The positives are that we didn't concede a goal and Marseille had one shot on target and we know in the final third we can do better.
"We took four points from Marseille in two games. We are in a strong position. It's good that we didn't concede."
