The Stoke winger posted two pictures on Instagram showing his left arm in a bandage with the caption “next step surgery…one of those things”.
The FAI said: “James McClean has been ruled out of our UEFA Nations League opener with a wrist injury sustained in training.
“The midfielder will undergo surgery today. We wish James a speedy recovery.”
The 29-year-old also misses out on the friendly with Poland.
McClean is a regular starter for Martin O’Neill, who is already without a number of players through injury.Alan Judge, Jeff Hendrick, Conor Hourihane, Alan Browne, Shaun Williams, David Meyler, Daryl Horgan and Callum O’Dowda are the remaining midfielders in the squad.
Defender Shane Duffy (groin) and midfielder David Meyler (knee) sat out training on Monday, but both players were involved in the session on Tuesday, which also included goalkeeper Sean McDermott and forward Jonathan Walters after they linked up with the squad.
Republic of Ireland Squad
Goalkeepers: Colin Doyle (Hearts), Sean McDermott (Kristiansund BK), Darren Randolph (Middlesbrough)Defenders: Seamus Coleman (Everton), Cyrus Christie (Fulham), Matt Doherty (Wolverhampton Wanderers), Shane Duffy (Brighton & Hove Albion), Richard Keogh (Derby County), Ciaran Clark (Newcastle United), Kevin Long, Stephen Ward (Burnley), John Egan, Enda Stevens (Sheffield United)
Midfielders: Alan Judge (Brentford), Jeff Hendrick (Burnley), Conor Hourihane (Aston Villa), Alan Browne (Preston North End), Shaun Williams (Millwall), David Meyler (Reading), Daryl Horgan (Hibernian), Callum O’Dowda (Bristol City)
Forwards: Jonathan Walters (Ipswich Town*), Graham Burke, Callum Robinson (Preston North End), Aiden O’Brien (Millwall)
Tags: