Theo Walcott
Minor surgery rules Walcott out of crucial World Cup qualifiers. (Reuters)

Arsenal's forward line has been struck another blow with confirmation that Theo Walcott will undergo a minor abdominal procedure that rules him out until after the international break.

The 24-year-old was withdrawn from Sunday's win over Stoke City with an abdominal problem that manager Arsene Wenger later admitted had mystified the Gunners' medical staff.

But after further examination it has been decided that the England forward will undergo minor abdominal surgery in order to rectify the issue, ruling him out of crucial World Cup qualifiers against Montenegro and Poland.

"Theo will be out for a few weeks," Wenger told the club's official website. "He has developed some damage to his posterior abdominal wall. It's not a hernia, but it's a little structural problem in his abdomen.

"He will have the procedure in Germany on Wednesday and, because it's so minor, we can begin his rehab immediately. We are pleased it's being dealt with quickly and he shouldn't miss too many Arsenal matches. But he will miss the forthcoming international matches with England."

Walcott's absence immediately rules him out of Arsenal's crucial Champions League clash at home to Napoli, in addition to Premier League trips away to Swansea and West Brom.

A possible return date is 19 October for a home game against Norwich City, but more pressingly the Gunners will hope to have the former Southampton starlet back for their trip to Champions League runners up Borussia Dortmund on 22 October.

The procedure shortens Wenger's forward options with Lukas Podolski already an absentee. The Germany international suffered a hamstring injury in Champions League qualifier against Fenerbache with an initial prognosis suggesting the Germany international would be ruled out for ten weeks.

However, after undergoing further tests with the German national team Podolski announced he feared his time on the side lines could stretch as far as three months. His teammate Alex Oxlade-Chamberlain is also unavailable for a similar period after injuring himself just a week into the new season.

Although the club's limited forward options have been supplemented by the added goal threat of Aaron Ramsey this season and the consistency of Olivier Giroud, Wenger may still be concerned with the lack of options in his squad.

18-year-old Serge Gnarby was drafted in to replace Walcott for Sunday's win over Stoke but with the club's only other forward options at present in Nicklas Bendtner and the untested Yaya Sanogo, the Gunners boss will be desperate to have his full range of options available as soon as possible.