Arsenal boss Arsene Wenger admits he cannot put a timescale on midfielder Tomas Rosicky's return from injury.

"Tomas has had surgery on his knee," Wenger told the club's official website. "His agent said he will be out for one or two months, but it will be longer. How long exactly, we don't know yet."

Wenger also revealed that midfielder Jack Wilshere was on schedule with his recovery from a hairline fracture in his ankle.

"We said Jack would be out for four weeks, and he's in the second week now so he's on schedule," added the Frenchman.