Last month, Havertz underwent surgery on his knee in an injury he picked up after a substitute appearance in the opening Premier League game of the season against Manchester United and has been on the sidelines since.
The German international was out several months last season after suffering a hamstring injury during a training camp in Dubai in February. He only came back for the final two games of the campaign in what has been an injury filled few years for the striker.
Now, Arteta has given a worrying update on the veteran striker who will not be back for The Gunners for some time.
"With Kai, we know that it will be months with him. I don’t know if it can be weeks, you never know because this is Kai and he’s a different specimen," he said.
"We really miss him. Hopefully, he will be back, and back for the long term as well, so it is very important to look after that knee. So far, he’s progressing pretty well."
Arsenal take on League One side Port Vale in the Carabao Cup on Wednesday looking to get back to winning ways. Arteta will be without the likes of Havertz, William Saliba, Martin Odegaard and a number of other players as their injury crisis worsens.