The 23-year-old has not made a first team appearance for the Gunners for almost two years after being sent out on loan last campaign.
Wenger told ESPN FC that the former France Under-21 international has a mystery calf injury and he is keeping the details “confidential” as he doesn’t have the required the knowledge to explain the problem accurately:
“He had a real medical problem that I cannot explain to you here, because it is a confidential problem. Not a secret problem, but it is medical, I cannot speak about that. He has no life-threatening problem but he had a long-term injury, and I am not specialized enough to explain to you exactly what it is in his calf. But we had to rest him completely.”
Over the past couple of years Sanogo has been loaned out to three clubs but it would be a stretch to say any of them have been a success. He failed to score in the league on his first loan spell at Crystal Palace, although he did score against Southampton in the FA Cup.
At Ajax he failed to make an impression while during his time at Charlton Athletic in the second half of last season, he scored three goals in one match in a 4-3 defeat to Reading but did not score again for the Addicks.