"It's been an emotional week, it's been surreal. I've dreaded this day for a long time (but) it's the right time for me," Ireland's most prolific goal-scorer told a news conference on Monday.
"To the fans, it's been an incredible journey and something I'll never forget. Wednesday night will be very emotional."
The 36-year-old Keane, who is also Ireland's most capped player with 145 appearances, announced his impending retirement last week and will make his final appearance in a friendly against Oman in Dublin on Wednesday.
"I've had so many wonderful memories but it's the right time," said Keane who has scored 67 goals for his country in an 18-year career.
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"All I ever wanted was to do my best for my country," added Keane who plays for Los Angeles Galaxy. "I think I did okay.
"The defining moment of my career was being given the Ireland captain's armband at the age of 26."
Keane made his international debut at the age of 18 against Czech Republic in 1998. His club career took him to Wolverhampton Wanderers, Coventry City, Inter Milan, Leeds United, Tottenham Hotspur, Liverpool, Celtic, West Ham United and Aston Villa before he moved to Los Angeles.
(Writing by Clare Fallon; Editing by Tony Jimenez)
