That's U.S. soccer superstar Megan Rapinoe getting very real about the postponed summer games ... saying she's having a hard time seeing how the event goes on even in 2021.

"The more I think about it logistically," Rapinoe says, "just bringing everybody together like that with the absence of drug therapies or anything like that just seems difficult."

Of course, the Olympics were previously set to kick off in just a few weeks ... but the coronavirus pandemic forced officials to bump the competition to next summer.

International Olympics Committee spokespeople seem confident the event will go on then without a hitch ... but Rapinoe told CNN's David Axelrod on "The Axe Files" podcast this week she's skeptical.

"I guess we'll see," Rapinoe says. "I don't want to be in the prediction business, but we'll see."

A cancellation or even another postponement of the Olympics would likely spell the end of Rapinoe's time as an Olympian ... she's 34 years old now and retirement is on the horizon.

If it is ultimately the end ... Megan had a hell of a run, winning a gold medal for the U.S. back in 2012.