Robbie Keane will make a farewell appearance for the Republic of Ireland after being named in squad to play Oman.
Keane has been selected for the friendly but will not take his place for the World Cup qualifier with Serbia after announcing plans to retire this afternoon.
Shane Long, Jon Walters and Daryl Murphy are the attacking options for the clash in Belgrade.
There are no new faces in O'Neill's 28, with the majority of the Euro 2016 squad selected for the upcoming games, while Shay Given has already announced his retirement.
Marc Wilson, Harry Arter, Paul McShane, David Forde, Alex Pearce and Callum O'Dowda all return to the squad having missed the summer's European championships in France.
Wilson and Arter missed out on the final 23 for France due to injury, while Forde, McShane, Pearce and O'Dowda were cut ahead of the tournament.
Seamus Coleman has been included in the squad, however, the Everton defender is nursing an ankle injury and may be a doubt for the upcoming fixtures.
John O'Shea and Jeff Hendrick are also carrying injuries going into these games and all three will be assessed by the Ireland medical team upon reporting for duty on Sunday.
Shane Duffy has also been ommitted from the squad as the Blackburn Rovers centre-half is suspended for the trip to Belgrade for that opening World Cup qualifier.
BREAKING: Martin O'Neill has announced his squad for the upcoming games against Oman and Serbia! #COYBIG pic.twitter.com/c9oq3G9N7l
— FAIreland (@FAIreland) August 24, 2016
"After the excitement of UEFA Euro 2016, it seems as if we had little time to enjoy some excellent performances during that tournament," said O'Neill.
"The World Cup qualifying campaign is already upon us and we have a difficult set of fixtures in the coming months.
"The visit of Oman to the Aviva Stadium reminds us of the game they played in Dublin two years ago. That took place immediately before we embarked on our European qualifying campaign.
"This game is ideal preparation for our first qualifier against Serbia in Belgrade a few days later. The Oman game also gives us the chance to play in front of Ireland supporters who enhanced their own reputation in France. We are looking forward to both games."
Ireland play Oman in a friendly at the Aviva Stadium on 31 August ahead of the trip to Serbia on 5 September.
Republic of Ireland squad to face Oman (31 August) and Serbia (5 September):
Goalkeepers: Randolph, Westwood, Forde
Defenders: Christie, Coleman, Keogh, O’Shea, Pearce, Wilson, Clark, McShane, Ward
Midfielders: Brady, McCarthy, Hendrick, Arter, Kane, Whelan, Meyler, Quinn, McGeady, McClean, O’Dowda, Hoolahan
Forwards: Keane (Oman game only), Long, Murphy, Walters
