Tyler explained that Gingrich has "business entanglements'' and "contractual obligations'' that legally prevent him from immediately creating an exploratory campaign. He added that Republicans shouldn't see Gingrich's absence as a sign that he is leaning against a presidential bid.
"I think people already understand that he's serious,'' he said.
With Mississippi Gov. Haley Barbour (R) taking himself out of the race last week, the crop of debate contenders is quickly winnowing. Former Massachusetts Gov. Mitt Romney (R) and Rep. Michele Bachmann (R-Minn.) have not announced yet whether they will participate.
"Rep. Bachmann told us that she is considering participating, so I would say she's 50/50 at this moment,'' said Michael Clemente, Vice President of FOX News. "Gov. Romney's staff said they have not made a decision yet.''
Other potential candidates, including Indiana Gov. Mitch Daniels (R), Amb. To China Jon Huntsman, former Arkansas Gov. Mike Huckabee (R) and former Alaska Gov. Sarah Palin (R), are also not planning to attend the debate.