ABC producers may want to order some TheraFlu for the cast of Dancing With The Stars. Boy are this season’s pros droppin’ like flies.

On Monday night’s performance show, pro dancer Anna Trebunskaya, who was eliminated earlier this season with Chuck Liddell, will be filling in for Lacey Schwimmer with Iron Chef America’s Mark Dacascos, as Schwimmer battles a bout with the flu. Lacey is the third DWTS dancer to get sick with the flu this season; pro dancers Derek Hough and Mark Ballas waged war with the virus last month.

“Guys I’m super sad to be sick today. Ugh,” Lacey Tweeted Monday.

Anna tweeted about working hard at rehearsals with Mark over the weekend, and then tweeted Sunday night: “At this point it is what it is…Fingers crossed. A little luck would be helpful too.”