Wenger had to withdraw the Czech Republic midfielder halfway through his side's 2-0 Barclays Premier League win over Stoke yesterday.

The former Borussia Dortmund midfielder spent 18 months on the sidelines before making his comeback from a series of hamstring and knee injuries against Manchester City in September.

Wenger has used Rosicky sparingly since his return but is now facing up to the fact he could be without the £6.7million player for up to a month.

"He's devastated and I am as well," Wenger said.

"Before the (Stoke) match I told myself 'he has played the whole game on Wednesday, should I take the gamble or not as it was such an important game?'. But by half-time he was struggling."

Wenger also had to do without Croatia striker Eduardo for 18 months after he broke his leg in a horrific tackle by Birmingham's Martin Taylor in 2008.

The 26-year-old took time to regain his full fitness following the injury and Wenger believes Rosicky is having the same problem.

"It's a vicious circle when you have been out for a long time. Eduardo had not played for 18 months, Tomas has not played for 18 months," the 60-year-old said.

"When you come back, one or two games, your body has to get used to producing the energy levels again and it's difficult. Nobody masters that.

"The first impression for me is that it won't be longer than a month but it's a groin problem so we have to see the scan in 48 hours which grade it is - grade one is 10 days but grade 3 is three."

Wenger went into the match a squad ravaged by injury.

William Gallas (hamstring), Emmanuel Eboue (muscle), Armand Traore (hamstring) and Andrey Arshavin (ankle) all picked up knocks during the match while Eduardo (thigh) was a late withdrawal from the matchday squad.

Gael Clichy (back), Abou Diaby (calf) and Nicklas Bendtner (groin) missed the win and are all doubts for next weekend's game with Liverpool while Johan Djourou (knee), Kieran Gibbs (foot) and Robin van Persie (ankle) are long-term absentees.

Arsenal are eight points off the top of the table and Wenger admits the Gunners' injuries have given their top four rivals the edge in this season's title race.

"We pick up more injuries than the other big teams, that is true," Wenger said.

"You cannot say there is not a reason for it but we have not found it yet.

"It's the worst season for injuries for us. And they are all in the same area - in the offensive side. Last year it was in the defensive side."

Russian playmaker Arshavin was the star of the show at the Emirates yesterday as he scored one and won a penalty - which Cesc Fabregas missed - as the Gunners returned to winning ways after two straight defeats.

Arshavin impressed as a lone striker in the absence of Van Persie, who is out until April after picking up his ankle during Holland's friendly with Italy last month.

Wenger admits he is uncertain whether Arshavin will be able to lead the line until Van Persie returns and has admitted he may have to enter the transfer market in January for a striker.

Bordeaux striker Marouane Chamakh has been linked with a move to the club but Wenger has warned that it will be tough to find a striker who is able to fill Van Persie's boots in January.

"I want to see if we are still in this same position at the beginning of January," Wenger said.

"But let's not dream too much that in January we will be able to find a world class player, because that is what is needed to improve our squad, and who is not cup-tied in Europe and who is free. You need a good Father Christmas for that."