Republic of Ireland midfielder Glenn Whelan is a doubt for the pivotal European Championship qualifier against Denmark on November 18th.
The 35-year-old picked up a hamstring injury in Hearts' Scottish League Cup semi-final defeat to Rangers.
With only two weeks until the visit of the Danes to Dublin, it's a concern for manager Mick McCarthy.
The boss is already without the suspended Seamus Coleman, and Matt Doherty's participation is not certain.
Wolves defender Doherty sustained a recurrence of a knee problem against Arsenal. The seriousness of it has yet to be determined. It could mean McCarthy calling up Dundalk's Sean Gannon.
Goalkeeper Darren Randolph is still not out of the woods. He has been suffering from a thigh injury and played no part in Middlesbrough's game at Derby County.
Glenn Whelan has suffered a revival in fortunes under McCarthy and was one of the brighter lights in the defeat to Switzerland. His absence could allow Alan Browne or Josh Cullen the opportunity to be part of the fray.
The news is better regarding Shane Duffy and John Egan, who should both be fit. Ciaran Clark is also in the frame having featured well for Newcastle in their 3-2 victory over West Ham United.
The Boys in Green will qualify for the finals if they beat Denmark.