Before his acting career took off, Line of Duty star Martin Compston was a professional footballer. The Scottish actor is now best known for his role as DS Steve Arnott in the hit BBC drama. The 41-year-old is set to lace up his boots for Soccer Aid at Old Trafford, with kick off on Sunday evening at 7.30pm. Compston will line up for the Rest of the World against England, with former Italy star Leonardo Bonucci among his team-mates. However, Compston was also a pro footballer in Scotland before focusing his energy on becoming an actor. In his early football career, he had stints with Aberdeen and Morton. The Line of Duty actor even played two senior matches for Morton at the end of the 2001/02 season, but without much success. His first appearance resulted in a 4-0 defeat against Alloa Athletic, while his second – another 4-0 defeat, this time against Queen of the South – saw Morton relegated from the Scottish Second Division. On Si Ferry's Open Goal podcast , Compston previously discussed his brief football career. He explained that he was first spotted while playing in a Scottish underage cup final against a Celtic side which included future Man Utd star Darren Fletcher. After a stint with his hometown club, he was signed by Aberdeen where he played alongside future Premier League ace Dean Windass. Compston even captained the Aberdeen youth team for a short period, but the actor knew when his time was up at the club. "I remember I was captain at a game and one of the top scouts came down, and we got beat off an East Kilbride select," Compston said in 2019. "I went, 'That's that f*****!'" After his stint at Aberdeen, Compston found himself back at Morton in the Scottish Second Division. "It just wasn't a good time to be at the club," the actor admitted. "They'd just gone down to the second division and we were struggling. "It was a mad time. We were full-time the YTS [Youth Team Scholarship] players. There was only three or four of us cleaning 40 pairs of boots and cleaning the stadium. "The first team were coming in training at night. There was a lot of hanging about. I felt more like a cleaner than a football player. "I made my debut when I was 17," Compston recalled. "We were away to Alloa. I knew they were only going to pitch me in if we were well up or well down. "I felt terrible, Alloa were winning 2-0 with 40 minutes left and they put a third one in and I was like, 'You beauty.' "The last game of the season, we had to win to stay up and we were playing Queen of the South who had to win to win the league. It was a sell-out, 14,000. The atmosphere was unbelievable." However, the day didn't go entirely smoothly. "There was some b******... at half-time, I knew I was going on. So I'm spraying balls about," Compston said. "It smashed somebody and he's run on and rugby tackled me. The stewards were just all laughing. It was nerve-wracking. It was Scottish second division football but it's like, 'You've done that.'" Compston began acting during his football career after he secured a role in Ken Loach's film 'Sweet Sixteen' while still with Morton. "It worked out perfect," Compston explained. "I'd just finished my exams and I'd got my Morton contract. The auditions were at the end of the year. "I went to [Morton manager] Peter Cormack and asked if it was alright to miss a couple of days of pre-season. We filmed it in the close season. He said, 'You're a fit boy, you'll be fine.' I finished filming and went back to Greenock Morton. "I remember being gutted because in the programme notes, the players were asked who's their favourite actor and not one of them said me. I thought one of them, for a joke, would throw my name in there!" Despite Loach being impressed by Compston's acting ability, the director advised him to stick to football. However, the Line of Duty star didn't heed that advice and auditioned for a Heartbeat spin-off called The Royal. He had been sent the wrong script but still got the part and from then on his mind was set. "That was a big wake-up call," Compston said. "They don't know who I am. They hadn't seen Sweet Sixteen. To get that, I said, 'OK, I'm alright at this.' "Morton weren't going through the best of times. I was driving up the road one day, passing Cappielow [Greenock Morton's stadium] and I just went in and said [to manager Dave McPherson], 'I think I'm going to give this acting a crack.' He said, 'Sorry to lose you,' but I didn't find it too hard to be honest."