Arsenal midfielder Cesc Fabregas is set to be out of action until April with a knee injury.
The Spaniard was substituted at half-time in Arsenal’s 1-1 draw against Liverpool on Sunday following a challenge with Xabi Alonso.
Fabregas, who had only recently returned to fitness following a problem with the same knee, will now miss most of the rest of the season.
Fabregas replaced William Gallas as Arsenal captain in November and Wenger admits it is a major blow to lose him.
“The news is not good because it is a partial rupture of the medial knee ligament that is taking us three to four months,” Wenger told Sky Sports News.
“We count four. He will be working hard to return earlier but we count four months.
“We will miss him of course but we have to find a way to compensate for the fact that he will not be on the pitch.
“I am sure we can deal with it and when he comes back he can help us to get over the line in the final months.”
Wenger added that he had no complaints over Alonso’s tackle, saying: “The challenge was fair and honest.
“It is the kind of thing that can happen and you have to accept. It was purely accidental.”
Wenger conceded that he may now have to move into the transfer market in January to provide cover for the loss of the Spaniard.
He added: “It is more likely yes, but we also have internal solutions. We are not desperate.”
Asked about Zenit St Petersburg playmaker Andrei Arshavin, Wenger added: “At the moment nobody is going out and nobody is coming in.”