Republic of Ireland midfielder Anthony Pilkington is a doubt for Friday's game against Latvia because of a dead leg.
The Norwich player will remain with the Norfolk club until Thursday as his progress is monitored.
Injury rules out Robbie Brady and Ciaran Clark from Martin O'Neill's opening two games in charge.
The Republic face the Latvians in Dublin in the first of two friendlies, with the second against Poland in Poznan on 19 November.
Hull winger Brady has a groin injury, while Aston Villa defender Clark is suffering from a foot tendon problem.
Pilkington was forced off with the leg injury during Norwich's win over West Ham on Saturday.
No additional players are being called into the squad for the double-header.
Experienced defender Richard Dunne was omitted from the original squad announced last week as he continues to recover from a groin problem.
Irish Under-21 boss Noel King, who took charge for the final two World Cup qualifiers last month, selected a 27-man squad for the fixtures.
New Republic manager O'Neill and his assistant Roy Keane signed two-year contracts last week and O'Neill was introduced to the media at a news conference on Saturday.
QPR central defender Dunne is still trying to overcome the groin complaint which sidelined him for the whole of last season.
Uncapped Newcastle goalkeeper Rob Elliot retains his place and Reading's Alex Pearce and Brighton's Stephen Ward are also included.
West Ham full-back Joey O'Brien has also been offered a chance to impress the new management team.
There is also room for midfielder Andy Reid, who was exiled from the international scene under former manager Giovanni Trapattoni.
Republic of Ireland squad: David Forde (Millwall), Keiren Westwood (Sunderland), Rob Elliot (Newcastle); Sean St Ledger (Leicester), Marc Wilson (Stoke), Seamus Coleman (Everton), John O'Shea (Sunderland), Alex Pearce (Reading), Stephen Kelly (Reading), Joey O'Brien (West Ham), James McCarthy (Everton), Stephen Ward (Brighton); Glenn Whelan (Stoke), Paul Green (Leeds), Andy Reid (Nottingham Forest), Aiden McGeady (Spartak Moscow), Anthony Pilkington (Norwich), James McClean (Wigan), Stephen Quinn (Hull), Wes Hoolahan (Norwich City); Shane Long (West Brom), Robbie Keane (LA Galaxy), Jon Walters (Stoke), Kevin Doyle (Wolves), Anthony Stokes (Celtic).