Things are about to get nasty in Donald Trump's boardroom.

The casting rumors for Season 5 of 'Celebrity Apprentice' have been flying fast and furious! Earlier this week, People reported that 80s singing sensation Debbie Gibson and 'American Idol' alum Clay Aiken have been confirmed as contestants.

Three-time Sports-Illustrated Swimsuit Issue cover girl Cheryl Tiegs is also reportedly joining the Season 5 cast alongside race car driver Marco Andretti.

The casting rumor mill's been working overtime as production gets underway on 'Celebrity Apprentice' Season 5, and now it looks like Donald Trump will have some really feisty characters on his hands.

'People' reports that '80s warbler and star of such awesome TV movies as 'Mega Python vs. Gatoroid' Debbie Deborah Gibson and 'American Idol' vet Clay Aiken have been confirmed as contestants.

They'll be sitting in the boardroom alongside previously announced contestants Cheryl Tiegs and Marco Andretti. And that's not all: 'Real Housewives' star Teresa "Table Flipper" Giudice and writer Victoria Gotti are also said to have joined the cast.

Donald Trump's 'The Celebrity Apprentice' is about to start filming its fifth season, and judging by some of these casting rumors, this might just be one of its most entertaining seasons yet.

Three-time Sports Illustrated Swimsuit Issue cover girl Cheryl Tiegs is reportedly joining the Season 5 cast alongside race car driver Marco Andretti, reports Entertainment Weekly.

Another possible cast member is former Danity Kane singer and reality star Aubrey O'Day. Sources confirmed to Life & Style magazine that O'Day is headed to the show, adding, "Aubrey is so excited to be part of the show."