The BBC confirmed that the 85-year-old presenter will not feature on the Saturday night live show.
"Sir Bruce Forsyth has the flu and therefore isn't feeling well enough to present tomorrow's Strictly Come Dancing on BBC One," a BBC spokesperson told Digital Spy.
"The show looks forward to his return next week. Claudia Winkleman will step in to replace him alongside Tess Daly on tomorrow night's show."
Winkleman replaced Forsyth as co-presenter of the pre-recorded Sunday night results show in 2010.
Forsyth has dropped hints of retirement in recent years and said that he and the BBC will "come to another arrangement" about his future on the show.
As in 2012, the broadcaster will have a reduced role on the 2013 show and be replaced by Winkleman for three weeks of live Saturday performance shows on the upcoming run.