Arsenal were reminded on Tuesday that their revival hinges clearly on one man – Robin Van Persie.
Take him away, and the team looks dangerously like the Gunners of earlier in the season – lacking bite.
Arsene Wenger insisted he started Robin van Persie on the bench because he was "tired", but that only served to augment RVP’s importance to the side.
Arsenal could have reached the last 16 of the Champions League with a victory against Marseille at the Emirates.
Instead they drew.
Van Persie, who hit a hat-trick in Saturday's 5-3 win at Chelsea, did not come on until the 62nd minute and even he could not get a goal.
Wenger said: "The reason I left Robin out was physical tiredness — that's all. He would have to play 50 matches a year. He cannot play 50 games.”
That will be a stark reminder to the Emirates from a very realistic Wenger.
Arsenal took away the fact that they did not concede a goal.
Defender Thomas Vermaelen, who completed the full 90 minutes, said: "It was tough. But the most important thing was the clean sheet."