Arsenal manager Arsene Wenger accepts Robin van Persie may well get the 'green light' to face Chelsea on Sunday, but is not about to take a big gamble with his team selection.
Holland striker Van Persie returned to action against Steaua Bucharest in midweek following almost two months out with a knee problem.
While the seven-goal forward looked sharp, the 24-year-old is the first to admit he is short of match fitness, completing just over an hour on Wednesday night.
With injury concerns over Cesc Fabregas, Mathieu Flamini and Alex Hleb, Wenger knows not to expect too much, too soon heading into the top-of-the-table showdown at Emirates Stadium.
The Arsenal manager said: 'At the moment, Robin does not have the green light medically.
'Once he gets that, we have to test him on the pitch with the other players and then we can make a decision.'
Wenger maintained it was still 'very early' to make any predictions as to the likelihood of his midfield trio returning to the squad on Sunday, and refused to be drawn on whether Jens Lehmann would retain the goalkeeper's jersey after his recall last night.
He said: 'They are practising, but not with the team. They are not in normal training.
'Who will come back into normal training before Sunday? It could be one, two or three.
'It is too early to say, and the selection will depend on that because you can gamble on one or two - but not five.'
The Gunners hold a slender one-point lead over Manchester United heading into this weekend's fixtures, which also sees the Red Devils head to Liverpool on Sunday lunchtime.
Victory for Chelsea, themselves on an impressive 16-match unbeaten run, would move them level with their opponents.
After Arsenal suffered a surprise defeat at struggling Middlesbrough last week, Van Persie knows there can be little margin for error.
'Almost everyone is waiting for us to fall down - but we are not going to fall down,' he said.
'Of course we are going to lose maybe two or three games and have a few draws. That's normal.
'But I am at the training ground every single day and I know what these guys are capable of. These are serious guys.'
Arsenal players, directors and staff are set to take part in the `Be a Gooner. Be a Giver' campaign ahead of the Chelsea match by donating a day's pay to the club's charity of the season, TreeHouse - which deals with autism education.
Captain William Gallas said: 'We are united on the pitch and we are united off it. We don't want to just talk about helping TreeHouse, we want to make a real difference.
'I hope that the fans can also make a small donation so it will be a real team effort.'
Meanwhile, Levski Sofia striker Nikolai Dimitrov claims he is set for a trial with the Gunners.
The 20-year-old has scored nine goals in the 32 games he has played for the club, who were Bulgarian champions for the past two seasons.