LONDON -- Arsene Wenger says Arsenal striker Yaya Sanogo remains sidelined with a long-term injury, but said he could not disclose details about what he called a "confidential" calf problem.
Sanogo has been out since the summer after going on loan last season, and has not made an Arsenal appearance since December 2014.
And Wenger said the 23-year-old French forward had to be shut down completely because of a complicated calf problem.
"He had a real medical problem that I cannot explain to you here, because it is a confidential problem," Wenger said after Arsenal's 2-0 loss to Southampton in the EFL Cup on Wednesday.
"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."
Arsenal are also without forward Danny Welbeck, who is closing in on a return after a long-term knee injury. Wenger said Welbeck should be back in full training in December.
"He is not far," the Arsenal boss said.
However, it remains unclear when Spanish midfielder Santi Cazorla could be back in the squad. Cazorla is struggling with an inflamed Achilles heel, and Wenger said there's no way of saying when the problem will go away.
"I don't know, honestly. It's just inflammation, that can go in two days or two weeks, I don't know," Wenger said. "He's not had a setback, it's just inflammation that is still there."