Roy Keane has admitted James McCarthy is "very doubtful" to make the Republic of Ireland's World Cup qualifier against Wales this Friday night, but refused to dwell on the camp's injury crisis.

Martin O'Neill has a lengthy list of absentees, with the panel being hit by withdrawal after withdrawal in the run-up to the Aviva Stadium showdown.

McCarthy missed Everton's Premier League defeat of Hull at the weekend due to a hamstring problem, and Keane revealed any hope of the midfielder recovering in time for Friday's battle now looks lost.

"James didn't train today," the assistant boss said.

"I would say he is very doubtful. I think he is due to do some running today, but if he doesn't join in with the group tomorrow, it'll be very doubtful for him."

McCarthy's likely absence comes after it was confirmed Daryl Murphy is out due to a calf injury.

The Newcastle United striker joins Wes Hoolahan (thigh), Shane Duffy (foot), Ciaran Clarke (knee) and Harry Arter (calf) on the absentee list, with Robbie Brady suspended.

On a more positive note, Keane expects Seamus Coleman and Jonny Hayes to return to training tomorrow, both having sat it out at Abbottstown on Tuesday as a precaution.

Keane also praised in-form Preston winger Aiden McGeady, and insisted the Irish will not use their depleted squad as an excuse to fail in their hunt for a precious Group D victory.

"We're delighted for Aiden (McGeady)," Keane added. "I've seen him a couple of times recently. He looks sharper and has added goals to his game.

"We've got to focus on the game and the lads who are here. We've a good group of players and we'll be ready for Friday. No excuses.

"We're disappointed for the number of the lads missing out. We've got plenty of good players here so we'll take it as it comes. There's not much we can do, we're not in control of it.

"If you think our mindset is to get a draw then you are sadly mistaken. We are here to win.

"We're always confident going into games, particularly at home. These players have never let us down and will give it their all."

Republic of Ireland squad as it stands

Goalkeepers: Darren Randolph, Keiren Westwood, Colin Doyle

Defenders: Seamus Coleman, Cyrus Christie, Richard Keogh, Alex Pearce, John O'Shea, Andy Boyle, John Egan, Stephen Ward

Midfielders: Aiden McGeady, Glenn Whelan, James McCarthy, Jeff Hendrick, Conor Hourihane, David Meyler, Eunan O'Kane, James McClean, Jonathan Hayes, Daryl Horgan, Callum O'Dowda

Strikers: Jonathan Walters, Shane Long, Kevin Doyle

Watch Republic of Ireland v Wales live on RTÉ2 from 7pm Friday, listen live on 2fm's Game On and follow our live blog on RTE.ie and the News Now app.