Hull City's Alex Bruce has been handed his first Northern Ireland call-up after his decision to switch allegiance from the Republic of Ireland.
Manager Michael O'Neill has included the defender in the squad for the World Cup qualifier against Portugal.
Bruce won his two Republic caps in friendlies in 2007 and 2008.
Another Hull defender Joe Dudgeon is also handed a first call-up with David Healy returning to the squad but goalkeeper Lee Camp is not included.
Nottingham Forest keeper Camp lost the Northern Ireland number one jersey for last month's opening World Cup qualifier against Russia in Moscow and then opted out of the home game against Luxembourg for personal reasons.
Roy Carroll played between the posts in last month's two qualifiers and joined in the squad for the Porto clash by St Johnstone's Alan Mannus and Falkirk's Michael McGovern.
Manager O'Neill has acknowledged that there is no imminent expectation of England Under-21 international Camp returning to the Northern Ireland squad.
"Lee obviously left the squad between Luxembourg and Russia, and at that time, he was stating the involvement in international football at that minute was neither beneficial to his career nor his personal circumstances," said O'Neill.
"We need to let Lee sort some things out and then let him decide whether he wants to be available for future call ups."
Because both of Bruce's Republic caps were in friendlies, he is eligible to represent Northern Ireland and he replaces suspended centre-back Gareth McAuley in O'Neill's squad.
In recent years, several Northern Ireland-born players have switched allegiance south of the border.
These include Sunderland's James McClean, Everton duo Darron Gibson and Shane Duffy plus Stoke's Marc Wilson.
Bruce, the son of Hull manager Steve Bruce, was eligible for international football for Northern Ireland, the Republic of Ireland and England, where he was born.
He was called up by Northern Ireland Under-21s but opted to play for the Republic Under-21s instead.
Bruce then made his Republic senior debut against Ecuador in New York in 2007 and played against Poland a year later at Croke Park but losing his place in Giovanni Trapattoni's squad.
He also captained the Republic's B team in a game against Nottingham Forest in 2008 but O'Neill is delighted to have the Hull defender available to him.
"The Fifa paperwork for Alex was all in place before I took over. It wasn't a case of me being involved in that process; that took place under Nigel Worthington but Alex wasn't featuring much in the second half of last season so wasn't picked," added O'Neill.
"This season he has been playing regularly and doing well so it was an easy decision to make."
O'Neill has played down suggestions that Bruce's switch may not prove popular with Northern Ireland fans.
"It's not an issue for me at all." he said.
"Players have options in relation to their international futures, Alex has decided now on Northern Ireland and I'm focused on that. The past is the past."
Northern Ireland's record goalscorer Healy returns after missing the opening qualifiers because of a lack of competitive football.
Peterborough's Grant McCann is also recalled while Burnley's Martin Paterson and Celtic's Pat McCourt return after injury.
Chris Brunt and Jamie Ward are both unavailable because of hamstring injuries.
Northern Ireland squad
Goalkeepers: Roy Carroll (Olympiakos), Alan Mannus (St Johnstone), Michael McGovern (Falkirk)
Defenders: Aaron Hughes (Fulham), Ryan McGivern (Manchester City), Jonny Evans (Manchester United), Craig Cathcart (Blackpool), Alex Bruce (Hull), James McPake (Hibernian), Joe Dudgeon (Hull)
Midfielders: Chris Baird (Fulham), Steven Davis (Southampton), Grant McCann (Peterborough), Oliver Norwood (Huddersfield), Corry Evans (Hull), Niall McGinn (Aberdeen), Shane Ferguson (Newcastle), Pat McCourt (Celtic), Josh Carson (Ipswich)
Forwards: Martin Paterson (Burnley), David Healy (Bury), Dean Shiels (Rangers), Kyle Lafferty (FC Sion), Will Grigg (Walsall)