Former Northern Ireland and Queens Park Rangers captain Alan McDonald has died suddenly at the age of 48.
McDonald, who managed Glentoran when they won the Irish League championship in 2009, collapsed while playing golf on Saturday morning.
The Belfast-born centre-half famously played in the Northern Ireland team which drew 0-0 against England in 1985 to qualify for the World Cup finals.
McDonald won 52 international caps, scoring three goals.
The news of McDonald's death will come as a huge shock to the football community in Northern Ireland.
He owned a trophy business in Bangor, Co Down, which had previously been run by his Northern Ireland team-mate Billy Hamilton.
McDonald made more than 400 appearances for London club QPR and was in the team which reached the League Cup final in 1986, losing 3-0 to Oxford United.
He then had spells with Charlton, on loan, and Swindon Town.
After retiring from playing, he served for a time as assistant coach of the Northern Ireland Under-21 side.
When Northern Ireland reached the World Cup finals in 1986 under manager Billy Bingham, McDonald played in matches against Algeria, Spain and Brazil.
John O'Neill, who played alongside McDonald for Northern Ireland and QPR, said he had fond memories of 'Big Mac'.
"When he came into the Northern Ireland team he had a cockiness about him, but he carried it so well because out on the pitch he was prepared to listen to the experienced players," said O'Neill.
"He put in a tremendous performance in his debut against Romania and matched it in that second appearance against England at Wembley.
"Alan will be badly missed because he was a character and there are not many of them around these days."
McDonald had a close affinity with Irish League club Crusaders where brother Roy is goalkeeping coach.
Crues manager Stephen Baxter said: "I have spoken with Roy and the family is in a complete state of shock. Everyone at Crusaders knows the McDonald family so well, we are devastated.
"Alan always thought of everyone else first - he wanted the best for other people.
"He loved his football and did a tremendous job at Glentoran. It was disappointing how it all ended for him there."
Former Northern Ireland manager Sammy McIlroy, a close friend and former team-mate of McDonald's, said: "I'm shell-shocked. Words can't even enter my head at the moment.
"Forty-eight is so young. Alan was always larger than life - during his career and after.
"I have just spoken to Norman Whiteside and he is devastated."
The funeral service will be in Ballygowan Presbyerian Church at 12:00 BST on Thursday, 28 June.