Simon Cowell misses Louis Walsh on 'The X Factor'.

Simon Cowell

Simon Cowell

The talent show boss - who judges the show alongside Robbie Williams, Ayda Field and Louis Tomlinson - has admitted it feels different being on the panel without the long-running judge, but joked the music mogul could always make a return as a contestant.

Speaking to Lizzie Cundy at the Health Lottery Afternoon Tea event, he said: "Yes I am [missing Louis]. But you know, he still does 'Ireland's Got Talent' and he can come back ... as a contestant.

"We have the Overs category so we would have to have the older and older category. For the over 80s."

Although Louis, 66, announced he was quitting after 13 years before the current 'X Factor' series, he has recently praised the singing competition and thinks it's a step above rival reality shows.

He previously said: "I have nothing negative to say about 'X Factor', it's the best show in the world. 'Strictly'? That's for older people, I watch 'X Factor.' "

The music manager has been tuning into the current run, and he refused to criticise the panel, instead heaping praise on 'Angels' hitmaker Robbie.

He added: "Of course I've been watching. Robbie is great, I've loved Robbie. I'm not saying anything bad. I talked to Simon twice today."

Releasing a statement over the summer, Louis revealed he was bowing out of the show after more than a decade.

He explained: "I've had a fantastic 13 years on 'The X Factor' but the show needs a change and I'm ready to leave."