The two streaming TV stars, who studied drama together at the Royal Scottish Academy, recently got together for an interview for Square Mile magazine and offered an insight into their decades' old friendship.
While the pair admitted it had been "at least ten years" since they'd been in the same room, Tom, 42, and Sam, 40, revealed that they once almost worked together on Outlander and said they wouldn't rule it out in the future.
WATCH: Season 5B of Lucifer is coming to Netflix in May
"These days everyone knows you from Outlander but I've known you for a lot longer than that," Tom began before revealing that he nearly landed a major role in the series. "I auditioned for Outlander, not for Jamie Fraser but for Tobias Menzies' part, 'Black Jack' Randall. I remember reading the script thinking, 'This is really good.'"
Sam replied: "Firstly, dude, I'm not sure how I'd have felt having you, I don't know, assault me shall we say," before going on to say that the two would have had a great time together on set.
"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." He added: "It's a great part. Tobias, of course, does an amazing job but that would have been so different."
The Lucifer actor almost played Tobia Menzie's role Frank Randall in the show
Later in the conversation, Sam discussed his favourite co-stars on the show and dropped a hint that he would still like to see the Netflix star join the cast. He said: "Each actor comes on with their own energy and new life. It's so important to have great actors surrounding you. We're very lucky. Suzanne Smith does a great job in casting," adding: "We're still waiting for you, though."
Tom coyly replied: "Well, I'm nearly finished [filming Lucifer]. If Covid ever lets us finish this job, then yes."
Lucifer season six finished filming this month
So could it be on the cards? Just this week, Sam left a touching comment on his friend's recent Instagram post about his final day on the set of Lucifer.
"Congrats buddy!!!! What a legacy. Should be proud to complete that journey! On to the next..." Sam wrote as Tom shared a black and white picture to mark his final day of filming the Netflix series.
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