Back in 2009, he was one of a cast of unknowns entering the third series of Channel 4's teen-acting-talent production-line, Skins.
They are both very busy all the time with work but they could make it work." Especially for the benefit of the promotional tour.
This year, O'Connell has proved himself as one of Britain's most exhilarating young actors in both the prison drama Starred Up and this month's Troubles thriller '71.
Not bad for a "mouthy gobshite" from Derby."A character like Eric..." he says, of his breakthrough lead film role in Starred Up, "I'm never too far from that version of grief, mentally, in terms of being able to relate.
Let's overlook the minor detail that they're both starring in a film together and this just may be a handy way of getting said film's name out there... Let's just take off the cynical cap and just go with the idea that they actually find each other attractive.
The model - who has been linked to the likes of Harry Styles and Jake Bugg in the past - met the 24-year-old on the set of forthcoming movie, : "Jack and Cara get on really well.
With a script by Gregory Burke, who wrote the National Theatre of Scotland's hit play Black Watch, '71 tells the story of Private Gary Hook, played by O'Connell, a young British soldier who finishes training expecting his regiment to be stationed in peaceful Germany.