Will Grigg will miss Northern Ireland's World Cup qualifier against the Czech Republic due to personal reasons, while Burton's Tom Flanagan and Dundee loanee Michael Duffy have won their first senior call-ups.
It is understood Wigan striker Grigg’s partner is due to give birth and he will therefore remain at home while Michael O’Neill’s squad head to Prague for the first game of the 2018 World Cup qualification campaign.
Burton defender Flanagan and midfielder Duffy, whose parent club is Celtic, will link up with O'Neill's squad for the first time having played for the Under-21s in the past while striker Liam Boyce, who narrowly missed out on a place in the 23-man squad for Euro 2016, is recalled.
From the 23 players O'Neill took to the country's maiden European Championship finals in France, only Chris Baird has announced his international retirement, though there is no place in this squad for either 38-year-old Roy Carroll or 36-year-old Aaron Hughes.
Uncapped Hartlepool goalkeeper Trevor Carson has been brought in as one of Michael McGovern's back-ups instead of Linfield's Carroll, while Hughes is considered to be behind fitness-wise having moved to the Indian Super League, which does not begin until December.
Gareth McAuley, whose own goal ended Northern Ireland’s time in France, will continue his international career at the age of 36.
As well as Boyce's return, there is also a recall for Peterborough full back Michael Smith, another from the group of five that was trimmed from the original 28-man group O'Neill had named in his extended Euros squad.
O’Neill revealed Grigg requested to be left out from international commitments, with the team due to go to Austria for a training camp next week before heading on to Prague.
“Will asked to be excused,” O’Neill said on Sky Sports News HQ. “His partner is due (to have) a child and, given that the game is away as well, it’s slightly more difficult if he was needed.
“He just felt in this situation that he would be better to stay at home and he asked not to be selected for this squad.”
The transfer window will shut before Northern Ireland take to the field against the Czech Republic, and defender Jonny Evans may have switched clubs before he next pulls on the green jersey.
Arsenal are thought to be keen on the 28-year-old West Brom player, who enhanced his reputation during an impressive Euros campaign.
“Jonny was outstanding in France,” O’Neill added. “He can switch in and out of systems. He’s a top-level player and could play in a top-four Premier League club. The interest from Arsenal doesn’t surprise me.”
NORTHERN IRELAND (Squad for the World Cup qualifier against the Czech Republic in Prague on September 4th): McGovern (Norwich), Mannus (St Johnstone), Carson (Hartlepool), McAuley (West Brom), J Evans (West Brom), Cathcart (Watford), McLaughlin (Fleetwood), Hodson (Rangers), Smith (Peterborough), Flanagan (Burton), Davis (Southampton), McGinn (Aberdeen), Norwood (Brighton), C Evans (Blackburn), Ward (Nottingham Forest), Ferguson (Millwall), Dallas (Leeds), McNair (Sunderland), Duffy (Dundee), Lafferty (Norwich), Magennis (Charlton), Washington (QPR), Boyce (Ross County).