Republic of Ireland manager Martin O'Neill may have to plan without Richard Keogh for the World Cup play-offs against Denmark after the Derby County defender limped off for the Rams at the weekend.

The 31-year-old has struggled to dislodge the first-choice partnership of Shane Duffy and Ciaran Clarke in the international fold, and is now facing a battle to be fit for Saturday's first-leg in Copenhagen, and possibly the return game four days later in Dublin.

The experienced defender was substituted after just eight minutes in the 4-2 Championship defeat to Reading and manager Gary Rowett has cast doubt on the defender capped 18 times for his country being fit for either leg.

"Richard came off with a quad strain - I don't know how bad it is but I would suggest it wouldn't be a good idea for him to travel. We hope it [the injury] turns out to be not too bad," he said.

Keogh's last competitive outing for Ireland coming in the 0-0 draw away to Wales last March.

The Irish squad will meet up today for their first training session ahead of the crunch play-off.

O’Neill is already without the services of striker Sean Maguire, ruled out with a hamstring injury.

The Preston North End striker is expected to be sidelined for up to three months as he is set to undergo surgery

James McCarthy has been named in the 34-man squad for Saturday night’s first leg in Copenhagen, but with just one competitive club game under his belt this season, is still in a race to prove match fitness. O'Neill is alrready shorn the midfield services of the suspended David Meyler.

Long-serving defender John O'Shea had a minor calf strain for Sunderland in their derby defeat to Middlesbrough at the weekend, but should be fine for the weekend.

The Sunderland captain played the full 90 minutes in Sunday's 1-0 home defeat that sees the Black Cats remain rooted to the foot for the Championship table.

Denmark too have injury concerns mounting ahead of Saturday night.

Live coverage of Denmark v Ireland on RTÉ Two (7.25pm), live radio commentary on RTÉ Radio One's Saturday Sport and live blog on RTÉ.ie from 6pm.