The German is into the final six months of his contract at Emirates Stadium and he will not be signing a new deal.
Mustafi can leave for free in the summer and is drawing interest from clubs in Italy, but it had been speculated he could leave now.
That is likely to be the case with fellow defender Sokratis Papastathopoulos, who also has six months on his deal but could leave now as Genoa and Real Betis are chasing him.
Arteta, however, has suggested that may not be the case with Mustafi and the centre-back could stay with Arsenal until his contract expires in the summer.
“His future right now is here. I’m trying to help,” said Arteta.
“We have Papa that probably is going to leave the club in this window, William [Saliba] that has already gone on loan, so we don't have that many [centre-backs] right now.
“Gabi [Magalhaes] has been out now for a period, David [Luiz] has been injured, so the situation is completely different to before.
“Musti came back from a really difficult injury when he got injured at the end of last season. Up to that period I think he was doing really well, I think his performances were increasing and getting better and better.
“When he came back it was a moment when we had seven or eight centre-backs, so he had to get his performance level up.
“I think physically he still needed some time, then he started to play some games in Europe which I think he did well in as well.
“And now it’s about when do you make the next step to be a starter, and the reality is that we have to change for different reasons, use different personnel.
“He’s been very close in a few games, but now we’ve found as well a partnership that is giving us clean sheets and sometimes when you do that it's difficult to change, but he's still in contention.”