Jonny Evans and Steven Davis will miss Northern Ireland's friendlies against Malta and Ukraine while Conor Bradley and Sam McClelland have been handed their first senior call-ups by Ian Baraclough.
Evans, 33, has been nursing a foot injury that the defender sustained in Leicester City's FA Cup final triumph over Chelsea earlier this month and he was not named in Brendan Rodgers' squads for their final two Premier League games of the season.
Thirty-six-year-old captain Steven Davis meanwhile has been given a break following a long season during which he became Britain's most-capped international male footballer and won the Scottish Premiership with Rangers.
Corry Evans has not been included in Baraclough's team as he is without a club after being released by Blackburn Rovers and therefore the midfielder does not have injury insurance cover.
Seventeen-year-old Liverpool right-back Conor Bradley has been included for the first time. He featured for the Reds in the recent FA Youth Cup final against Aston Villa and has previously represented Northern Ireland at U17 level. Bradley captained Northern Ireland Schoolboys to the Victory Shield in 2018.
McClelland, 19, has been a regular for Chelsea's U23s this season, and the Coleraine-born centre-half has previously represented his country at U19 and U17 level.
Leeds United's player of the year and 52-time capped Stuart Dallas is likely to captain the side in the absence of experienced duo Davis and Evans.
Newcastle full-back Jamal Lewis meanwhile is out with a groin injury. The 23-year-old has featured for only six minutes of action for his club Newcastle United in the Premier League since February.
Familiar faces including Kilmarnock's Kyle Lafferty, Watford's Craig Cathcart, Middlesbrough's Paddy McNair and Aberdeen's Niall McGinn all made Baraclough's squad.
Northern Ireland will play Malta on Sunday evening in Klagenfurt, Austria before heading to Dnipro to take on Ukraine next Thursday.
Goalkeepers: Bailey Peacock-Farrell (Burnley), Conor Hazard (Celtic), Liam Hughes (Liverpool).
Defenders: Craig Cathcart (Watford), Stuart Dallas (Leeds United), Shane Ferguson (Millwall), Paddy McNair (Middlesbrough), Daniel Ballard (Arsenal - on loan at Blackpool), Ciaron Brown (Cardiff City), Sam McClelland (Chelsea), Conor Bradley (Liverpool).
Midfielders: Niall McGinn (Aberdeen), George Saville (Middlesbrough), Jordan Thompson (Stoke City), Alistair McCann (St Johnstone), Alfie McCalmont (Leeds United), Jordan Jones (Rangers), Gavin Whyte (Cardiff City), Ethan Galbraith (Manchester United).
Forwards: Kyle Lafferty (Kilmarnock), Josh Magennis (Hull City), Liam Boyce (Heart of Midlothian), Shayne Lavery (Linfield), Dion Charles (Accrington Stanley), Paul Smyth (Queens Park Rangers).
Baraclough unfazed over NI contract talk
Baraclough's contract as Northern Ireland manager expires at the end of the year. The 50-year-old took over from Michael O'Neill in June 2020 after three years in charge of the country's U21 squad.
Baraclough though says he remains focused on securing qualification for Norther Ireland's next major tournament and not on any talk surrounding his future.
"Others will make that decision," he told Sky Sports News when asked about whether he had contemplated staying on as manager beyond the end of the year.
"Hopefully I've got a really good working relationship with those people. They know what my plans are for the players going forward. For a country like ours it probably goes in cycles.
"Before Michael O'Neill qualified for the Euros in 2016 it was 1986 since the last one.
"Hopefully we don't have to wait a period of time like that and we're building towards the next time we can qualify, we have a good group of players.
"We understand where we are but we're learning as a group and bringing through those young players is a part of us being successful."
In a season where international sides have had to grapple with ever-changing Covid-19 requirements and protocols, Northern Ireland's game against Turkey originally scheduled for May 31 was scrapped after the country was placed on the UK government's red list for travel.
Concerning the uncertain year for football, O'Neill said: "It's been a challenging year for everybody, we've had to run with the different protocols, staying in bubbles, dealing with triple-headers and travel restrictions.
"Making sure everyone has been safe and sound has been the main priority and that continues."
On the two upcoming friendlies, he added: "I want to win two games. These may be classed as friendlies but there's no such thing as friendlies for me, for the group of players that can't be the mindset.
"We are building towards September and we have a few young players in the squad but whoever comes in needs to be competitive and needs to realise there is a challenge for places.
"We are assessing and we go into those September games in a positive frame of mind."