The 33-year-old has been absent since October 2016 and admitted earlier this week that a return early next season is likely the best he can hope for.
Fan favourite Cazorla recently underwent a 10th operation to rectify a long-running Achilles injury, which he feared would see him lose his ankle due to infection.
Wenger is refusing to offer the Spaniard any assurances as he continues to recover, with his contract due to expire in less than six months' time.
"A new contract? That depends on his medical availability at the top level. We have to assess that until the end of the season - if Santi is fit and available to play, then yes. Of course, we have to see that," he told reporters at Friday's press conference.
"That is why I tell you it is a complicated situation because first of all we love him, second of all he is a great football player. But the third situation is that you need to be healthy today to play at the intensity that is needed in the Premier League. So we have to see if he can absorb that or not.
"I sent him a message two weeks ago and wished him well, hoping to see him soon. He has not come back yet because he has just had surgery. The medical people know much better than I do whether he will play again in 2018 before the end of the season. Before the end of the season will be hard for him."
Cazorla has won two FA Cups with Arsenal since joining from Malaga for £10m in 2012.