England international, Theo Walcott was expected to start the 3-1 triumph over Stoke City which catapulted the Gunners to the top of the table, but he was withdrawn just before the start of the match with an unknown injury suffered in training.

He could take no part in the encounter with Stoke as injury kept him off the substitutes’ bench as well. Walcott had reportedly suffered a strain prior to victory over Marseille in mid-week, and that intensified hours before kick-off against Stoke.

According to Metro, Wenger admitted that he is in the dark over Walcott’s injury. He revealed that the 24-year-old has an abdominal muscle problem and was unable to put a timescale on his return.

He said, “He had an abdominal muscle problem, I don’t really know what it is. Nobody can tell me whether it is just a question of days.”

He added, “He had a test before the game and I decided to play him but he had a little problem before the Marseille game [last week] and it then became a bit worse. It’s a bit mysterious, because we don’t really know what it is.”

The pacey forward was replaced by the unfamiliar Serge Gnabry who put in a decent shift. Stoke have ditched their physical long-ball style of play under Mark Hughes, and were beautifully passing it around as they opened up the home side’s defence a couple of times.

With injuries mounting up, Walcott’s absence was expected to be felt as Cameron equalised Ramsey’s opening goal inside the first five minutes. However, Mesut Ozil proved to be the difference with three superb deliveries from set pieces which ensured Arsenal continued their fine run of form to sit joint top of the Premier League alongside fierce rivals Tottenham Hotspurs.

However, Arsenal have crucial fixtures coming up and Wenger will be hoping he can have a fit Walcott to fire in the goals. They are paired with West Brom away from home in a Capital One cup clash on Wednesday, before they take on Michael Laudrup’s Swansea City in the Premier League on Saturday.