The 43-year-old singer-songwriter has spoken out following the news his band Take That's first album since the departure of both Jason Orange and previously Robbie, 'III', will go up against their bandmates surprise new record 'Under the Radar'.
However, the former 'X Factor' judge revealed Robbie - who first left Take That in 1995 before rejoining in 2010 and quitting again in 2012 - had told him and his remaining bandmates Mark Owen and Howard Donald about his new album, but failed to mention it would be released on the same day as theirs.
Gary told The Sun newspaper: ''I only found out about that on Sunday (30.11.14).
''It's funny, because we have obviously spent a lot of time in the studio with Rob.
''About two years ago he said, 'I've got all these songs and I don't know what to do with them so I'm going to put them on an album one day'.
''So it's not a surprise he's doing it, but it is a surprise it's out this week.
''He played us most of them and there are some cracking songs because whatever Rob writes is good.''
Meanwhile, the 'These Days' hitmaker claims both Robbie and Jason will be returning to the band in the future.
He said: ''Take That is five people. Exactly when they come back is up to them. That will keep it interesting.''
We spoke to The Corrs' frontwoman about her festive new release.
We want to speak to the Grammys manager...
From child star to rockstar, Taylor Momsen has been through quite the career evolution in her time - and all by the age of 27!
True stories of music and the macabre...
Doja Cat isn't the only one who shocked the world with a new image.
Eight stunning covers of Nine Inch Nails as we welcome them into the Rock and Roll Hall of Fame.