Quique Setien says he has not been told Arthur will be leaving Barcelona for Juventus, urging the Brazil international to stay focused for the rest of the season.
Arthur is reportedly set to join Serie A champions Juve for €80million, with the more experienced Miralem Pjanic potentially heading in the opposite direction for €70m.
Barca take on Celta Vigo at Balaidos on Saturday and Setien insisted the former Gremio midfielder remains available for selection and could feature.
"In principle I still have Arthur. He is important like the rest. He will train and in principle he will travel and has the possibility of playing," said the Barca boss.
"I hope all this noise does not affect him and that if he plays, he tries to give the best of himself.
"Any player who is in such a situation must make it clear the season is not over, win a title and leave a good impression until the last day he is here.
"I do not take it for granted that he is going to leave. The club has not informed me Arthur is leaving. He will be with us until the last game of the season.
"If it happens, I will try to convince him to leave a good impression. The most important thing is to be honest until the last day and I am convinced he is."
Setien was unwilling to comment on the possible signing of Pjanic and suggested Arthur has struggled to adapt to the style of football he wants Barca to play.
"Since he has been with me, he has put a lot of interest in doing what we asked him to do," Setien said.
"Maybe he lacked a little continuity. It is not easy to change things in a footballer that other coaches told him were very good. When they tell him it is very good to keep the ball and we come and we want to play two touches, it is difficult.
"Yes, it's possible he lacked some physicality, but he is on the right track."