DES MOINES, Iowa — Hollow or not, Donald Trump’s threat to boycott the final GOP forum before Iowa votes has complicated Ted Cruz’s game plan, forcing the Texan to prepare for two different debates — one in which he tangles directly with the front-runner and another that sets up the senator as the largest target on stage.

With hours until debate time, Cruz’s campaign still says it thinks Trump’s pledge to skip the forum is a stunt. “Donald Trump will be at the debate,” Cruz spokesman Rick Tyler Tyler predicted. “Mark my words.”

In advance of the last pre-Iowa showdown, Cruz spent the day Wednesday holed up in debate preparations with his top brass. Campaign manager Jeff Roe, chief strategist Jason Johnson, Cruz's pollster and others all descended on Iowa ahead of the final five-day push to the caucuses.

If Trump sees through his promise to hold a rival event Thursday, the Cruz camp will use it as fresh ammunition for an assault on the New Yorker’s character, casting their fiercest rival for the GOP nomination as too emotional and self-centered to be trusted with the White House.

“What people will understand is Donald Trump, if he’s not there, made an emotional decision,” Tyler said. “That fits his erratic behavior, based on grievances that are petty and small. That’s what people will see.”

“He’s put himself first and the country second. Or third or fourth or somewhere,” Tyler added.

Cruz and Trump have been locked in what’s become a two-man race for first place in the first state, but polls suggest Trump has the momentum. The Manhattan businessman has led all but one of the 11 public polls in Iowa that have been released since the Des Moines Register/Bloomberg poll in early January showed Cruz with a narrow 3-point lead.

Cruz, a collegiate championship debater, clearly wants another shot at Trump. He immediately challenged him to a “mano-a-mano” debate after Trump announced his withdrawal. “Can we do it in Canada?” Trump mocked him on Twitter.

For Cruz, Trump’s threatened absence means that the other candidates who trail him in Iowa, such as Marco Rubio and Rand Paul, have only one leader to fire upon: him.

Paul, whose sagging showing in the polls caused him to miss the last debate, has been itching to take on Cruz. On Wednesday, Paul ripped Cruz for his more hawkish stands on foreign affairs in an email to his supporters. Trump’s nonappearance, Paul said on Fox News, should give him more time to make all his arguments.

“It’s sort of a double win for me; not only am I on the main stage, but we don’t have to put up with a lot of empty blather and boastfulness and calling people names,” Paul said.

Rubio has telegraphed his interest in going after Cruz’s past work as a lawyer for a Chinese company accused of stealing intellectual property from an American firm. The issue has yet to come up at a debate, but Rubio hammered Cruz for it earlier this week in Des Moines.

“When Ted Cruz had to choose as a lawyer, he was choosing to represent the Chinese,” Rubio told reporters. “You can’t go around saying you’re tough on China but then have a legal record in which you were paid a lot of money to defend the Chinese who had taken a product away from an American — unjustly, unfairly and illegally.”

The attack is a familiar one for Team Cruz. His 2012 Senate race opponent, David Dewhurst, used it aggressively. In a twist, the Dewhurst strategist who crafted those broadsides is now Cruz’s campaign manager, Roe.

There are other echoes of Cruz’s 2012 contest. In that race, Cruz mercilessly mocked Dewhurst for not doing enough debates and events with him, even sending someone in a duck outfit to trail him. Cruz touted the DuckingDewhurst.com domain then; after Trump’s treat, Cruz began promoting DuckingDonald.com.

Cruz wasn’t the only one hunkered down in a prep for an uncertain debate. The campaign trail in Iowa was far quieter than normal just days from the caucuses. Two of Cruz’s top surrogates, Rep. Steve King and former Gov. Rick Perry, campaigned without him during the day, holding events in Burlington and Iowa City.

Cruz was scheduled to headline an evening rally in West Des Moines. Rubio’s lone public event was also an evening rally, scheduled only five miles away.

But all eyes remain on Trump, who holds a rally and then is scheduled to appear on Fox’s Bill O’Reilly program late Wednesday, despite his boycott of the network’s debate the next night. Rival campaigns plan to tune in to see whether Trump, who mused about walking out on past debates but never followed through, reverses course.