Earlier this week, McFadden said that he is "ready" to reunite with his former bandmates to take on the newly-reformed Take That.
However, original member Shane Filan told The Sun that McFadden's offer will not be taken up.
Filan explained: "I don't think it's even remotely interesting if Brian came back.
"Brian left because he didn't like being in the band. It wasn't because we fell out. For us as a band, we never split up. We've kept going and are very happy.
"If another person came in it would be like restarting a new band."
Speaking on the comparisons between McFadden's prospective return and Robbie William's rejoining Take That, Filan said: "Robbie Williams coming back to Take That was a big announcement.
"He's the biggest male solo performer of the past 20 years. You can't compare it."
Fellow Westlife singer Kian Egan added: "[McFadden] doesn't live in this country and is not in the music industry anymore."