The Football Association of Ireland paid tribute to Derry City captain Ryan McBride on Monday after he died suddenly at the age of 27.
McBride, a close friend of Republic of Ireland winger James McClean, is reported to have died at home on Sunday. A cause of death has not been revealed.
"Irish football is in mourning with the loss of a true great of the game, with the shocking news about Ryan McBride's passing," FAI chief executive John Delaney said in a statement.
"I would like to pass on my deepest condolences to Ryan's family, friends, and his club, Derry City FC, for which he was their leader, their captain and their inspiration."
Tributes will be paid to McBride prior to Ireland's World Cup qualifier against Wales in Dublin on Friday.
Derry's league games against Limerick and Galway have been postponed, as well as all of Tuesday's matches in the first round of the League of Ireland Cup.
McBride made his debut for home-town team Derry in 2011 and made over 100 league appearances for the club.
Ireland manager Martin O'Neill, speaking at a press conference, said it was a "tragic event".
"I didn't know Ryan personally," he said. "James McClean was a close friend of his and is devastated."
A statement on Derry's official Facebook page read: "Derry City Football Club is deeply saddened by the untimely death of our captain, Ryan McBride.
"Our prayers and thoughts are with his father, Lexie, his sisters Colleen, Siuinin and Caitlain, and his partner Mairead, who are heartbroken at his loss.
"In the hearts and minds of all of us and long into the future Ryan McBride will be remembered as one of the greats of Derry City Football Club."