Democratic presidential nominee Hillary Clinton is scheduled to return to the campaign trail on Friday after taking a few days off to recuperate from pneumonia, MSNBC reported Tuesday. 

The network, citing what it said was a release from Clinton's campaign, said she was scheduled to appear at a "Black Women's Agenda" event in Washington, although it said if she were not feeling well that plan could change.

Clinton on Sunday left a Sept. 11 memorial service in New York City after nearly collapsing from deyhydration and overheating

Her doctor later issued a statement saying the candidate was experiencing "cough-related allergies" and had been diagnosed with pneumonia Friday. She was advised to rest and modify her schedule.

In an interview with CNN Monday evening, Clinton said she initially didn't think her bout of pneumonia was "not a big deal," not heeding her doctor's initial warning to get rest.

"I just want to get this over and done with and get back on the trail as soon as possible," she said. 

But this diagnosis has again raised questions about Clinton's level of transparency, an issue that has repeatedly dogged her campaign. 

In Monday's interview with CNN's Anderson Cooper, Clinton tried to shift the issue away from her transparency, or lack thereof, to Donald Trump's.

"Compare everything you know about me with my opponent. I think it's time he met the same level of disclosure that I have for years," she said.

"It's really past time for him to be held to the same standards, not just as me, but as anybody else who has sought this job."

Meanwhile, Trump will sit down with fellow reality star Dr. Mehmet Oz for an interview that will air Thursday, and bring added attention to the health of both candidates.  

Oz said Tuesday he will ask "pointed questions" about Trump's health, but also promised to not ask the candidate "questions he doesn't want to have answered."

Reuters contributed to this report.