Gareth McAuley celebrates after scoring for Northern Ireland against Ukraine in the Euro 2016 finals
Northern Ireland defender Gareth McAuley has returned to the squad for the final two World Cup qualifiers against Germany and Norway next month.
The West Brom player missed last month's wins over San Marino and Czech Republic because of a thigh injury.
Craig Cathcart (knee) is out while there are call-ups for uncapped pair Jordan Jones and George Saville.
NI have sealed a top-two spot but will finish second and progress to a likely play-off if they fail to beat Germany.
Northern Ireland host Group C leaders Germany on 5 October before facing Norway in Oslo three days later.
McAuley was forced off with a recurrence of a thigh injury in June's qualifier victory over Azerbaijan in June.
The 37-year-old, who has scored nine goals in 72 international appearances, is a key player for Northern Ireland and is expected to start in place of Cathcart against the Germans in Belfast.
Northern Ireland have won five matches in a row and kept five clean sheets
Kilmarnock's Jones and Millwall midfielder Saville are new faces in the 26-man panel named by O'Neill on Monday.
"Gareth would always be a big miss. His game time has been limited but McAuley is always one who you want in your squad," said O'Neill.
"Germany couldn't be more difficult - we couldn't have the game though at a better time and we have nothing to lose.
"After the players experienced the Euros, we want to experience a World Cup. But we have lots of work to do yet.
"Jordan Jones is quick, he's the sort of player fans will love. It's a great opportunity for him and he is only 22."
Germans eye finals
The world champions have a five-point advantage over Northern Ireland and just need to avoid defeat at Windsor Park to ensure a place in the finals in Russia next year.
Northern Ireland are well placed to finish as one of the eight best runners-up from the nine groups and make the play-offs in November.
They achieved their highest ever Fifa world ranking of 20th for September, a massive climb from 129th in September 2012.
Northern Ireland's ranking in October will determine if they are one of the four seeded teams, which would mean avoiding teams such as Portugal and Italy.
Northern Ireland squad
Goalkeepers: McGovern (Norwich City), Mannus (St Johnstone), Carroll (Linfield)
Defenders: Hughes (Hearts), G McAuley (West Brom), Evans (West Brom), Brunt (West Brom), C McLaughlin (Millwall), Hodson (Rangers), A Thompson (Bradford City loan), D Lafferty (Sheffield United), Flanagan (Burton Albion)
Midfielders: Davis (Southampton), McGinn (Gwangju), Norwood (Fulham loan), C Evans (Blackburn), Ferguson (Millwall), Dallas (Leeds), Lund (Burton Albion), Paton (St Johnstone), J Jones (Kilmarnock), G Saville (Millwall)
Strikers: K Lafferty (Hearts), Magennis (Charlton), Washington (QPR), McCartan (Bradford City)
Source: bbc.com