Arsenal midfielder Abou Diaby has been ruled out for three weeks with a thigh injury.
The midfielder suffered the injury attempting a shot at goal in the Gunners' 2-1 defeat against Chelsea on Saturday.
Diaby adds to Arsene Wenger's injury worries, with the Frenchman sweating on the fitness of Mikel Arteta and without Wojciech Szczesny for a further few weeks.
"Arteta will have a test tomorrow on an ankle injury. Diaby is out with a thigh injury.
"We are pleased with Wilshere, but we will take it slowly. He is exceptionally happy. Szczesny will be two or three weeks still."
Wenger is however boosted by the performance of new boy Santi Cazorla and praised the display of Keiran Gibbs ahead of his side's Champions League clash with Olympiakos on Wednesday.
"We are over the moon with Santi. He is not only an exceptional player, but a great person," added Wenger.
"Gibbs has found stability. I am very happy with his performances."