Republic of Ireland manager Stephen Kenny will be without first-choice left-back Darragh Leahy for the upcoming UEFA under-21 qualifiers against Italy and Iceland.
The Bohemians defender hasn't featured for his club since returning from the victory against Sweden with an ankle injury and his club boss Keith Long admitted earlier in the week that he looks set to miss the rest of the season.
There is some good news with Kenny able to include Southampton striker Michael Obafemi and Stoke stopper Nathan Collins in his 22-man squad.
Both were late injury withdrawals ahead of the back-to-back wins against Armenia and the Swedes.
Attacking midfielder Connor Ronan also returns to the squad having missed the previous games through injury.
Kenny's team will be looking to maintain their excellent form which has seen the side claim three wins from the opening three matches in Group One.
Ireland are set to face Italy at Tallaght Stadium on Thursday, October 10 before flying to Reykjavik to take on Iceland on Tuesday, October 15, with kick-off at 4pm (3pm local time).
It was announced last week that the fixture against Italy at Tallaght Stadium has sold out but the game will be live on eirSport, with kick-off at 8.05pm.
Republic of Ireland U-21 Squad
Goalkeepers: Caoimhin Kelleher (Liverpool), Gavin Bazunu (Manchester City)
Defenders: Danny McNamara (Newport County, on loan from Millwall), Lee O'Connor (Celtic), Dara O'Shea (West Bromwich Albion), Conor Masterson (QPR), Liam Scales (UCD AFC), Nathan Collins (Stoke City), Kameron Ledwidge (Southampton)
Midfielders: Jayson Molumby (Millwall, on loan from Brighton and Hove Albion), Jason Knight (Derby County), Conor Coventry (West Ham United), Jack Taylor (Barnet), Connor Ronan (DAC Dunajská Streda, on loan from Wolverhampton Wanderers), Dan Mandroiu (Bohemians), Gavin Kilkenny (AFC Bournemouth), Zack Elbouzedi (Waterford)
Forwards: Adam Idah (Norwich City), Troy Parrott (Tottenham Hotspur), Jonathan Afolabi (Celtic), Aaron Connolly (Brighton and Hove Albion), Michael Obafemi (Southampton)