Arsenal will discover tomorrow how long Theo Walcott will be unavailable with the ankle injury he sustained in England's 3-1 win over Switzerland yesterday, as another injury crisis envelops the club ahead of Saturday's visit of Bolton.

The club's medical staff examined the 21-year-old at their London Colney training complex, following a scan that was performed on the forward's ankle at a Swiss hospital after he was carried off in the 13th minute.

The scan relieved concern that Walcott would be out for a lengthy period after it showed that the ankle was strained rather than broken. Fabio Capello, the England manager, stated after the match that the winger had told him he believed it may be less than a fortnight before he can return.

His absence, though, means Arsène Wenger is now without Walcott, Robin van Persie, Samir Nasri, Nicklas Bendtner and Aaron Ramsey after only three games of the league season, which leaves the manager with just one front-line forward – Marouane Chamakh.

These absences mirror last season, during which Wenger often had to operate without a raft of first-team players who were all ruled out at the same time, while he also lost key performers, including Cesc Fábregas, Eduardo, Van Persie, William Gallas and Tomas Rosicky, to long-term injuries.

This suggests there may be a frailty in his squad and its ability to deal with the gruelling nine-month campaign. Leading into the pivotal Christmas period last season Van Persie and Bendtner were again unavailable, along with Gaël Clichy, Rosicky and Fábregas.

Just two months later Wenger was without five first-team players – Manuel Almunia, Gallas, Andrey Arshavin, Alex Song and Eduardo – ahead of the Champions League tie against Porto. Wenger has, though, been boosted by the return of Johan Djourou, who played for the reserves on Tuesday, and Song should also be available for selection to face Bolton.

Denílson, the Brazilian midfielder, may also feature on Saturday and he told ArsenalTV that the players must focus for the visit of Owen Coyle's side. "When you play Bolton you can't think that it is an easy game," he said. "You have to think it is a good game, a brilliant game and you have to win, the same as if you play Chelsea or Manchester United."