“Outlander” star Sam Heughan and actor Tom Ellis of “Lucifer” fame are longtime friends, and a new feature for Square Mile finds Ellis interviewing Heughan.

During their chat, Ellis shared a revelation with his pal that he’d never heard before: Ellis had once auditioned for a key role in “Outlander”.

“I’m going to let you into a little secret,” Ellis told Heughan. “I auditioned for ‘Outlander’, not for Jamie Fraser but for Tobias Menzies’ part, ‘Black Jack’ Randall.”

READ MORE: Sam Heughan Teases ‘Dark, Exciting’ New Season Of ‘Outlander’ On ‘GMA’: ‘The Fans Are Really Going To Love It

As viewers of “Outlander” will no doubt recall, Randall terrorized Heughan’s character for the show’s first few seasons, and brutally raped him in one of the series’ most infamous scenes.

Heughan shared his surprise. “Firstly, dude, I’m not sure how I’d have felt having you, I don’t know, assault me shall we say,” he said, admitting that Ellis playing Jamie’s rival would have been “tricky.”

However, Heughan conceded that Ellis would have done an excellent job with the dual roles of “Black Jack” and his descendent Frank Randall, husband of Claire (Caitriona Balfe).

READ MORE: ‘Outlander’ Teases Season 6 With Sneak Peek At New Scene

“I know we would have had a great time,” Heughan continued. “Actually, you would have been brilliant at that because Frank Randall is this charming, loveable character and then Black Jack, the other part you would have had to play, is just violent.”

Added Heughan: “It’s a great part. Tobias, of course, does an amazing job but that would have been so different.”

The sixth season of “Outlander” debuts Sunday, March 6 on W Network.