Mark Owen has predicted Robbie Williams will join Take That onstage "halfway through a show".
The 36-year-old singer thinks former band member Robbie - who the group have recently re-kindled their relationship with - could make a spontaneous return to the stage to perform with the group.
He said: "I've got a feeling that halfway through a show we might get a message saying he wants to come onstage and sing a song with us.
"I don't think it would ever be an organised thing. The nice thing for me is that we're seeing Rob, and it's great that we're all in contact with each other again."
Robbie extended an olive branch to his former bandmates - Mark, Gary Barlow, Jason Orange and Howard Donald - during the sessions for their latest album 'The Circus', and last week hinted he would like to re-join the group.
Robbie said: "Having met up with them I can tell you they're having a ball. I'm really proud. I love their new album 'The Circus' too - I haven't stopped listening to it. I'd love to be in the band again but I've got some unfinished business of my own to do first."
Robbie also revealed he has the band's 'TT' logo tattooed on his arm, in tribute to the group.