Shamrock Rovers star Jack Byrne and Bournemouth's League Cup penalty hero have both been included in Mick McCarthy's finalised squad for the upcoming internationals, however there is no room for Shane Long.
McCarthy's men face Switzerland in a "huge" Euro2020 qualifier on September 5 before a friendly with Bulgaria five days later.
Bournemouth goalkeeper Mark Travers saved three penalties to help his team advance in the League Cup against League Two side Forest Green.
Travers will be amongst fellow netminders Darren Randolph and Kieran Westwood in the squad.
One of the League of Ireland's form players, Jack Byrne, could make his debut while fellow midfielder James McCarthy is also retained in the squad.
After nearly two-years of injuries, McCarthy has moved Crystal Palace and his international manager watched him play against Colchester on Tuesday night.
Aston Villa's Conor Hourihane is in the squad after his two-goal appearance on Tuesday and there is also room in the squad for the likes of Glenn Whelan, the fit-again Alan Judge and Alan Browne.
A host of Premier League defenders are also included with captain Seamus Coleman, Wolves star Matt Doherty, Shane Duffy and Sheffield United players John Egan and Enda Stevens in the mix.
Bramall Lane attackers Callum Robinson and David McGoldrick are also included alongside Scott Hogan and Sean Maguire. However Southampton striker Shane Long has missed with the Tipperary man yet to feature for his club this season in the league.
Robbie Brady also misses out due to injury with he "has been close to a comeback with Burnley in the past few days but these games have just come too soon for him."
McCarthy told FAI.ie that game-time was a "big thing" in picking the squad.
"I named a 40-man provisional squad a fortnight ago because so many of the players had yet to play for their clubs but thankfully that situation has improved dramatically since then," McCarthy said
"I watched James McCarthy play the full 90 minutes for Palace in the Carabao Cup on Tuesday while Alan Kelly was at Burnley on Wednesday night to see Jeff Hendrick and Kevin Long start against Sunderland.
"Alan Browne is back in the team at Preston and Mark Travers started for Bournemouth on Wednesday and saved three penalties.
"Conor Hourihane scored two goals for Aston Villa at Crewe on Tuesday and Glenn Whelan is playing again now that he has signed for Hearts.
"It is great to have them back on the pitch ahead of such a big game against the Swiss and then for the friendly against Bulgaria.
“I’m also looking forward to seeing Jack Byrne in action for Rovers against Bohs on Friday night. He got two great goals in Waterford last week and he is the form player for Stephen Bradley right now.”
Michael Obafemi, who scored mid-week for Southampton is among a number of young players called up to Stephen Kenny's U21 squad as opposed the senior team.
Kenny's side have two European Championships qualifiers against Armenia and Sweden.
Tottenham's young star Troy Parrott, Stoke's Nathan Collins and Brighton forward Aaron Connolly will be lining out for the U21s.
Speaking about the young stars, McCarthy said: "I have spoken to Stephen [Kenny] and it is best for the players and our hopes of U21 qualification for them to be involved for the Armenia and Swedish games at this stage."
Ireland will play Switzerland on September 5 and Bulgaria on September 10.
Both games will be played in the Avivia Stadium and kick-off is 7.45pm.
Republic of Ireland Squad
Goalkeepers: Darren Randolph (Middlesbrough), Keiren Westwood (Sheffield Wednesday), Mark Travers (Bournemouth)
Defenders: Seamus Coleman (Everton), Matt Doherty (Wolverhampton Wanderers), Shane Duffy (Brighton & Hove Albion), Richard Keogh (Derby County), John Egan (Sheffield United), Kevin Long (Burnley), Enda Stevens (Sheffield United)
Midfielders: Alan Judge (Ipswich Town), Callum O’Dowda (Bristol City), Alan Browne (Preston North End), Jack Byrne (Shamrock Rovers), Jeff Hendrick (Burnley), Conor Hourihane (Aston Villa), James McCarthy (Crystal Palace), Glenn Whelan (Hearts), Josh Cullen (Charlton Athletic), James McClean (Stoke City), Ronan Curtis (Portsmouth)
Forwards: Callum Robinson (Sheffield United), Sean Maguire (Preston North End), Scott Hogan (Stoke City), David McGoldrick (Sheffield United)