Arsenal manager Mikel Arteta says Takehiro Tomiyasu injured his other calf in the win over Wolves on Thursday.
The Japan right-back only returned from a calf injury to face Wolves at the Emirates, which ended in a 2-1 win to Arsenal.
Asked about Tomiyasu's injury, Arteta said: "Yes, it was the other calf.
"So he came back and he was completely fine, and in training he felt the other calf.
"So this in an issue because he's a professional, who is giving absolutely everything to help us, and in the last few months he's not been fit."
Need a VPN? Or seeking to switch? Then support Tribal Football by clicking here to sign up with our official partners NordVPN. Not only will you receive the best VPN experience, but also great discounts by signing up via Tribal Football. Thanks for your support!