Bournemouth's Harry Arter looks likely to join the Republic of Ireland's lengthy absentees list for Thursday's World Cup qualifier against Georgia.
Republic assistant boss Roy Keane said on Tuesday that Arter's groin injury could keep him out of the Georgia game and Sunday's qualifier in Moldova.
On the plus side, James McCarthy came through training unscathed on Tuesday.
Daryl Murphy, Stephen Quinn and keeper Keiren Westwood are among seven players already ruled out of the squad.
The other absentees are Kevin Doyle, Aiden McGeady, Anthony Pilkington and Marc Wilson.
After their opening 2-2 draw in Serbia, the Republic face Georgia in Dublin before travelling to Moldova for Sunday's game.
Moldova were beaten 4-0 by Wales in Cardiff in their opening qualifier last month while Georgia lost 2-1 at home to Austria in their first game in Group D.
Arter misses Republic training
Keane said that Arter underwent a scan on Monday and did not take part in training on Tuesday morning.
"I think the scan was pretty positive but obviously the player himself feels still a bit tight," added the Republic assistant boss.
"If you don't train two days before a game then that is not good news.
"We hope it might settle down in the next few days and might be available for the second game. But we wouldn't be too hopeful once again."
Belgrade hero Murphy ruled out
Newcastle striker Murphy, who headed the late equaliser in Belgrade, has a calf injury.
Quinn (knee), keeper Westwood (thigh), Doyle (ankle), Aiden McGeady (hamstring) and Pilkington (quad muscle) are also injured while Bournemouth's Marc Wilson lack of recent club action has also resulted in him dropping out of the squad.
Like Murphy, Reading midfielder Quinn made a positive contribution when introduced off the bench in Belgrade.
The other players ruled out are also not regular starters, but the volume of injuries reduces Martin O'Neill's options for this week's qualifiers.
With Sheffield Wednesday's Westwood ruled out, Manchester City keeper Ian Lawlor has been promoted from the under-21 squad, while Aberdeen striker Adam Rooney has also been called up.
Keane also revealed that Salford-born Brentford striker Scott Hogan could be in line for a call-up to the Republic squad after scoring seven goals for the Championship club so far this season.
"The manager has touched base with the player and I think he is due to try meet up in the next few weeks. He looks a really good player, a proper goalscorer," said Keane of Hogan, who has three Irish grandparents.