But now the Cardiff actor is stepping on to “that pitch, in those football boots” as the show returns for a new season.
“It’s very surreal for me to be part of that Richmond world,” the actor tells Radio Wales.
Season 4 marks a dramatic shift for the show, with Ted returning from Kansas to coach AFC Richmond’s second-division women’s team, The Lady Greyhounds.
“It’s exactly the same set-up: you meet new people, you fall in love with these characters on, and off, the pitch. There’s all the coaching staff that you know and love, but with brand-new footballers,” says Rex. “It’s very exciting.”
Joining a cast which includes fan favourites Hannah Waddington, Brett Goldstein and star and co-creator Jason Sudeikis, Rex plays Siobhan, twin sister to Niamh (Aisling Sharkey), whose sibling rivalry sometimes spills on to the pitch.
“I love this character so much – I can’t wait for people to meet her,” Rex tells Eleri Sion on The Friday Afternoon Show. “She’s very passionate, very silly.”
A keen footballer from a young age, Rex describes the role as “a crazy matching of both my worlds”.
“I have been playing football for most of my life,” explains Rex. “Just me and my dad, at Heath Park, kicking a ball about, for most of my youth.
“I played in the school yard every lunchtime until my A levels – me and the boys. It’s been a big part of my life for a long time.”
But after giving up football training at 12, the actor “went off to drama school and forgot about it” – only returning to the pitch after moving to London.
Cue, the Ted Lasso audition.
“I had to send in a tape of my football skills,” says Rex, who made a tape in a London park.
“I remember when I went in for my first meeting, having sent off that tape, Theo – the casting director – was like, ‘you’re very good at football’. I was like: ‘yes, I am – remember that!”
“And lo and behold, here I am. So I’m very grateful.”