Democratic presidential nominee Hillary ClintonHillary Diane Rodham ClintonState Dept: Russia’s allegations about American citizens ‘absolutely absurd’ Trump on possible sit-down with Mueller: 'I've always wanted to do an interview' Election Countdown: Senate, House Dems build cash advantage | 2020 Dems slam Trump over Putin presser | Trump has M in war chest | Republican blasts parents for donating to rival | Ocasio-Cortez, Sanders to campaign in Kansas MORE’s campaign manager said on Sunday that he wants Donald TrumpDonald John TrumpIran claims it rejected Trump meeting requests 8 times ESPY host jokes Putin was as happy after Trump summit as Ovechkin winning Stanley Cup Russian ambassador: Trump made ‘verbal agreements’ with Putin 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.”