Fleetwood Mac are to hit the road again in 2009 though plans for Sheryl Crow joining the band are not "written in stone".
Guitarist Lindsey Buckingham said the Rumours rock legends are "looking at the idea of touring sometime in the first half of 2009" and could perform some new material.
But in response to rumours that Crow, friends with Fleetwood Mac's Stevie Nicks, may join the tour, Buckingham said that plans to add a new female singer to the lineup following the retirement of Christine McVie had not gone past the discussion stage.
Crow, 46, had told Spinner.com earlier this month that she and Fleetwood Mac "definitely have plans for collaborating in the future, and we'll see what happens".
However, Buckingham told Billboard.com: "I don't think anything is written in stone yet.
"I think we were all a little surprised [Crow] was announcing that to the world with such certainty," he went on.
"We have talked about the possibility of bringing another woman into the scene to kind of give Stevie a sort of foil and shake it up a little bit. [Crow] was certainly a name that has come up. We'll have to see."
Nicks, Buckingham's ex-wife, has been the only female in the hugely successful band since McVie retired in 1998, following the group's induction into the Rock And Roll Hall Of Fame.