The Destiny's Child singer is currently in Los Angeles and will not be able to fly back to London because of a "throat infection".
"Kelly is devastated she won't be here for this weekend's show," read a statement. "She is extremely ill with a viral throat infection and her doctors aren't permitting her to fly.
"Kelly will be returning to the show as soon as she has recovered. The girls have been in touch to wish her a speedy recovery and they can't wait for her to get back."
Nicole Scherzinger has since been rumoured to step in as cover for the ill judge.
According to The Mirror's TV reporter Mark Jefferies, Rowland's absence from rehearsals for this weekend's show caused "chaos".
Last week, Rowland left for a trip to Los Angeles, sparking rumours that she had fallen out with fellow judges Tulisa Contostavlos and Louis Walsh.
Contostavlos and Walsh accused Rowland's act Misha B of bullying fellow contestants on last week's show. Rowland told Contostavlos to "leave things backstage".
The Destiny's Child star later denied reports that she left her X Factor acts because of a fall-out with her fellow judges, insisting that her LA trip had been planned "for a long time".
Watch the video of Kelly Rowland's 'Down For Whatever' below: