The Switzerland international has been heavily linked with a move to Jose Mourinho's Roma, although the Gunners have reportedly offered him a new contract to convince him to stay.
Xhaka scored in Arsenal's 2-1 friendly loss to Chelsea at Emirates Stadium on Monday (AEST) after coming on to replace Thomas Partey, who appeared to injure his ankle in the first half.
With the former Atletico Madrid man set for scans, Arteta appears doubly determined to keep Xhaka in his squad.
"We just had a talk with the doctor and he'll have a scan tomorrow. At the moment, it's not looking good because he was in pain," Arteta said.
He then added on Xhaka: "Granit is going to stay with us. He's a key member of our squad and he wanted to play today - I think it's a very clear commitment from his side that he wants to be here."
Xhaka's goal cancelled out a good opener from Kai Havertz, but Tammy Abraham secured the win for European champions Chelsea after an error in possession by Hector Bellerin.
Despite the result, Arteta was pleased with elements of his side's display in front of an excitable crowd in north London.
"It was a great atmosphere, the fans were right behind the team. It was a great test for us," he said.
"I think we showed some really positive stuff and some worrying stuff when we gave the ball away in difficult positions."