Take That have plans to fully reform as a five-piece in 2017.
The singers reunited with Robbie Williams on 2010 album 'Progress' and though both he and Jason Orange aren't a part of the group's latest album 'III', the remaining members insist the pair will be back for their 25th anniversary.
Speaking to The Sun newspaper, Howard Donald explained: "We want to do something with the five of us. That will be great."
Gary added: "It would be nice to put all the music from the Nineties and now on one compilation and do a tour that would have to be bigger.
"Take That is five people. Exactly when they come back is up to them. That will keep it interesting."
He also joked that fans should now expect the line-up to change for every new record.
"Moving forward, I do think our fans need to get used to the fact that it's going to change -- maybe every album. I might be missing on the next one and Rob might come in instead of me. Actually, he'd better not do!"
Despite only just releasing 'III', the group are looking ahead to their next album and are confident Robbie will want to be a part of it.
Gary continued: "Rob will be back soon. We have a good time with Rob. He adores being in the studio and he loves the process of writing with us.
"We can't wait to start the next record now. We have that excitement in us.
"There's no way this is the last album. I feel this is what I've been put here to do."
Tagged in Gary Barlow Take That Mark Owen