Crawford Wilson, the club secretary, told UTV that 20 minutes into the match against Shankill United II he signalled to come off the pitch, due to the pain.
"Just with that he collapsed onto the pitch," Mr Wilson explained.
"Despite valiant efforts from local people and emergency services, they were not able to revive him."
Although a member of the football club, Saturday's clash was the young accountant's first game with the second team. Stuart's girlfriend was watching the match and rushed to his side as the tragedy unfolded.
Sometimes life throws things at you that no-one can explain.
John Brennan, cousin
Mr Wilson, whose son Alan was best friends with Stuart, said the Ross family were "absolutely distraught."
"Everyone at the club is totally devastated at what happened at the grounds yesterday," he said.
"I have been involved in football for over 40 years now and you never think that this would happen to your own club - especially someone who was a true gentleman like Stuart."
Mr Wilson said that the young man attended the gym most evenings after work in Larne.
"He probably would have been one of the fittest people on the team."
Alan Wilson, player/manager of the team, described the scene at the grounds.
"Everyone was running around frantically trying to help him and trying to get ambulances, trying to get gates opened, cars moved.
"In that sort of situation what can you do but panic straight away?"
John Brennan, a cousin, told UTV that Stuart was one of the "softest, nicest guys you'll ever meet."
"He just took everything in his stride, was so relaxed," he added.
" [He] never stressed. He was just about enjoying life. He was the heart and soul of this club.
"What can you say about the man? He was a gentleman, an absolute legend."
It is understood that a post-mortem is due to take place on Monday.