WWE star Seth Rollins may have been toeing the line between reality and kayfabe when he made some pointed comments about the idea of a UFC fighter transitioning to professional wrestling.

The world heavyweight champion told ESPN's Marc Raimondi he doesn't believe any UFC fighter would go full-time in WWE, citing the arduous year-round schedule.

"They don't have the stamina for it, man," he said. "They don't fight every single weekend, right? This championship goes everywhere."

Rollins cited Ronda Rousey as somebody who had a "tough" time going from UFC to WWE.

However, to say there isn't a UFC fighter who could succeed in WWE is a stretch when Shayna Baszler, Marina Shafir and Matt Riddle are all active performers at major promotions.

More than anything, Rollins' comments came off as foreshadowing a major storyline to come, especially with WWE and UFC's merger under the TKO Group Holdings umbrella company.

A major crossover between the two feels inevitable.