CNN  — 

Ben Carson gave a tepid explanation of his decision to endorse Donald Trump on Monday, saying even if Trump “turns out not to be such a great president … we’re only looking at four years.”

Carson told Newsmax TV that he backed his former Republican presidential rival because “I’m a big picture guy.”

“Even if Donald Trump turns out not to be such a great president, which I don’t think is the case, I think he’s going to surround himself with really good people,” Carson said. “But even if he didn’t, we’re only looking at four years as opposed to multiple generations, and perhaps the loss of the American dream forever.”

READ: Carson endorses Donald Trump

Noting that Trump would assemble a capable support system of “good people,” Carson also revealed he was promised a role in a potential Trump administration.

“I will be doing things as well,” he said. “Certainly in an advisory capacity (in Trump’s administration).”

“We haven’t handled out all the details but it is very important that we work together in this country,” he added. “Again, I’m not going to reveal any details about it right now because all of this is still very liquid.”

READ: Two Donald Trumps, or two Ben Carsons?

Hope Hicks, a spokeswoman for the Trump campaign, denied Carson had been promised a position.

“As stated by both Mr. Trump and Dr. Carson during Friday’s press conference, no role had been promised or even discussed. Both only stated that Dr. Carson will be involved with the campaign going forward,” she said.

CNN’s Kristen Holmes contributed to this report.