However, Louis insists he and the rest of One Direction - Liam Payne, Niall Horan and Harry Styles - understood Zayn's reasons for leaving and think it is fine he is now going his own way.
He said: "You know, I think we all kind of noticed that he wasn't thoroughly enjoying it and we were and you know it can be an intense job at times and I think it got a little bit too much for him and he wanted to be in a different place and that's fair enough and he's got his own way now so fair dos."
Elsewhere in the interview, Harry insisted he "didn't know" the group's song Perfect was speculated to be about his relationship with former girlfriend Taylor Swift and refused to confirm if that was the case.
He said: "OK, I didn't know that was the speculation.
"I'd say I think everyone writes from personal experience and I think you draw from lots of different things and songs aren't always necessarily about what people may take them to be about, sometimes they are."
Louis added: "The point of that song is often when we do meet people it is quite hectic and it is quite chaotic so it was kind of putting that into a song."
The full interview with One Direction can be seen on The Jonathan Ross Show, which airs in the UK on Saturday.
- Bang! Showbiz
