He said: "There is always the worry with Michael, because of recent years, over how often he is going to play. Players are no good to you if they are not playing and it is more painful than ever if you are having to pay them a lot of wages.
"A factor with Michael is there is no transfer fee, and that would be attractive for everybody. But you have got to look at the other things."
Coates reaffirmed that there had not yet been any approach for Owen and admitted: "We haven't really discussed Michael. We know he's about. He has been a terrific player, and he's a very nice man.
"I don't know what options Michael has got. Obviously, we are not privy to his position and what options he has got and where he might go. We will still keep an eye on it, that's about as much as I would say.
"He has been a fabulous player for Liverpool and England. He has had a lean time, but I am sure he doesn't feel finished and hopefully, from his point of view, he is not."