Arsenal will leave a decision on the fitness of captain Cesc Fabregas until the last possible moment as Arsene Wenger aims to keep his team top of the Barclays Premier League table after their match at title rivals Manchester United on Monday night.
The Spain midfielder limped off during the 2-0 Champions League defeat in Braga last month after suffering a fresh hamstring problem in what has been an injury-plagued campaign for the World Cup winner.
Arsenal head to the north-west having leapfrogged United, whose match against Blackpool was postponed.
Fabregas has offered no guarantees he will be ready to lead the side out at Old Trafford and Gunners boss Arsene Wenger is not ready to take any risks.
"We could have Cesc Fabregas [back], but there is a big uncertainty if he can be in the squad or not. That will be decided very late," Wenger said.
Arsenal are definitely without defender Kieran Gibbs, as the England full-back is set for three weeks on the sidelines with an ankle problem suffered in the 3-1 Champions League win over Partizan Belgrade on Wednesday night.
Wenger hopes the 21-year-old - who also suffered a metatarsal injury during November 2009 which sidelined him for the rest of the season - will soon be back in action.
"I am very disappointed [about it]. I hope it will not put in his mind that he is an injured player," said Wenger.
"It was just an accident and you cannot do anything about it.
"Time will help him get over that and it is not major damage in his ankle."
Regular left-back Gael Clichy could return after missing the Partizan game through illness, while Johan Djourou's thigh strain has responded well to rest and treatment.
Theo Walcott is also pressing for a place in the starting XI after coming off the bench on Wednesday night to net a well-taken goal as Arsenal moved into the last 16 of the Champions League.
While dressing room talk may be of a potential European clash with Barcelona or Real Madrid in February, Walcott maintains all the focus must now be on Old Trafford if Arsenal are to build on successive away wins over Wolves, Everton and Aston Villa.
"United have not lost in the league yet, so hopefully we can be the first to do that," the England forward said.
"Manchester United are not playing the best, but these are the games where they will step up.
"Yet if they are not playing well and still are second in the league, then we don't want to catch them on a good day.
"But we have just got to go there and play with no fear, express ourselves and then the best performance will come out.
"We need to get something there and the way we are playing away from home, we can beat anyone."Reuse content