Democratic presidential nominee Hillary ClintonHillary Diane Rodham ClintonIntel Dem decries White House 'gag order' after Bannon testimony 'Total free-for-all' as Bannon clashes with Intel members Mellman: On Political Authenticity (Part 2) MORE’s campaign manager said on Sunday that he wants Donald TrumpDonald John TrumpDems flip Wisconsin state Senate seat Sessions: 'We should be like Canada' in how we take in immigrants GOP rep: 'Sheet metal and garbage' everywhere in Haiti MORE to be called out if the Republican presidential nominee lies during the first debate Monday night.

“I think what needs to happen at this debate is the candidates need to present their capacity to serve as president and commander in chief. We think Hillary Clinton’s going to do that,” Robby Mook said on ABC’s “This Week.”

Mook added, however, that he is concerned about “some sort of double standard.”

“You know, Donald Trump can’t lie on that debate stage and win, or even get a passing grade. Donald Trump cannot demonstrate that he doesn’t have a command of the issues and get a passing grade,” he said.

“So all that we’re asking is that Donald Trump show that he is ready to be president of the United States.”

Mook said it would be “unfair to ask for Hillary … to play traffic cop” and present her own vision after host George Stephanopoulos noted that the debate commission has been clear that the moderator should “get out the way” and “just ask questions.”

“I think Donald Trump’s special. We haven’t seen anything like this. We normally go into a debate with two candidates who have a depth of experience, who have rolled out clear, concrete plans, and who don’t lie, frankly, as frequently as Donald Trump does,” Mook said.

"So we’re saying this is a special circumstance, a special debate, and Hillary should be given some time to actually talk about what she wants to do to make a difference in people’s lives. She shouldn’t have to spend the whole debate correcting the record.”