Boruc has made 50 appearances for Southampton since joining almost two years ago, but he has lost his No.1 position to summer signing Fraser Forster.
The Poland international was left out of last week’s squad for the 2-1 defeat by Liverpool and will again sit out Saturday’s home game against West Bromwich Albion.
Southampton boss Koeman understands why the 34-year-old wants to leave St Mary’s and is waiting to see what happens before the transfer window closes on September 1st.
“Boruc is training like he did before,” said Koeman.
“I spoke with him and he said he would like to move, that’s normal for his position, and until the transfer deadline he is not in the team.
“If he stays after then, it’s a new situation and we think about it. When he moves it will be best for Artur and best for the club.
“I’m not frustrated because I think it’s a normal situation of what he thinks of himself and that he wants to be in the Polish national team.
“To be part of that has to play and that’s normal, I can understand that because I like players who do everything to play, but it's difficult here because we made the situation here clear.”