When Kelly Rowland exits the U.K. version of "The X Factor," there will be an empty seat to fill. Possible replacements include Katy Perry and Nicole Scherzinger, according to longtime star Louis Walsh.

He told the Irish Herald newspaper, "I've worked with Nicole and Katy before and I would love to work with them again, they were fantastic."

There are five celebrities being considered to fill former Destiny Child star Rowland's seat. Current "X Factor" Australia judge and former Spice Girls star Melanie Brown, Anastacia and ex-judge Sharon Osbourne are also in the running.

Walsh added, "Mel B knows the format so well... Anastacia has sold millions of records and is a big star and I would give anything to work with Sharon again."
 
Walsh is a current judge along with Take That's Gary Barlow and pop star Tulisa Contostavlos.