The two clubs have fallen out after the failure to agree to a loan extension so Sailba can play the final.
Arteta said, "As you know, both clubs had some conversations, at the moment they haven't reached any agreement for him to be able to play in the final. At the end of the day he is our player and we want the best for him. We want to protect him and we want him in the best possible condition for us as well when he joins us but it is something that is being dealt with at club level."
Asked if he will sell any central defenders this summer, Arteta also stated: "We will see because Pablo (Mari) won't be available to start the season and Callum (Chambers) won't be available to start the season. We have nine games left until the end of the season, a lot of things can happen.
"William has had a lot of issues this season with injuries as well so he has not been a stable player in that sense so let's wait and see. At the moment we're going to have options and we will consider the situation with what is best to do in the future but we don't have much stability at the moment."