Jack Wilshere is making "slow progress" in his recovery from an ankle injury, says Arsenal manager Arsene Wenger.
However, Wenger said on Friday: "He is making slow progress, so we still monitor the situation at the moment.
"I told you the next three weeks would be decisive. Now we have two weeks in front of us and I cannot tell you more. I will not take any risk with him."
Wilshere has not played for Arsenal since suffering the injury in a friendly against New York Red Bulls on 31 July.
That followed a breakthrough season in which he made 49 appearances for the Gunners and five for England.
Meanwhile, Wenger has responded to amid a seventh successive trophyless season.
Former Gunners defender Campbell told BBC Sport: "You've got to ask yourself, where are Arsenal going? Do they want to actually win anything?
"You can have players for the future but it is about getting players who can make a difference now."
Wenger, who signed Campbell from Tottenham in 2001 and managed the centre-back until his departure for Portsmouth in 2006, gave a humorous reply.
"Sol Campbell has a lot of money, his gifts are welcome," said the Frenchman.
"If he gives us money, we will spend it, believe me. The best way always to give advice is to show example. Give your own money and we will spend it."
Five new players arrived at the Emirates Stadium in the final two days of the summer transfer window and Wenger's side won only one of their opening seven Premier League games.
Defeat at Tottenham on 2 October left them in 15th place in the Premier League, but 18 wins from the next 26 matches has lifted them to third with five games remaining.
"What has not changed at all is our policy - that we will be ambitious as ever and spend the money we have available," Wenger explained.
"We'll always spend money because we are very ambitious for top-class players and if we look at the history of our last 15 years we have always had top-class players and, incidentally, Sol Campbell is one of them.
"People forget we had a terrible start to the season down to the fact that we had injuries and transfers.
"Our ambition is in tact - to win the championship - and it depends now how we finish the season to decide how much we need to buy to have a good chance to win the championship next season."