... underfire Newcastle defender Shane Ferguson is included.
O'Neill's men face Uruguay in Montevideo on May 30 before taking on Chile in Valparaiso on June 4.
Ferguson has spent a season-long loan at Birmingham City but he struggled to hold down a place.
Alan Pardew has already told the full-back he won't have his contract renewed.
Northern Ireland squad to play Uruguay and Chile:-
R Carroll (Olympiacos), M McGovern (Falkirk), T Carson (Portsmouth), D Lafferty (Burnley), R McLaughlin (Liverpool), A Hughes (QPR), L McCullough (Doncaster), L Donnelly (Fulham), C Baird (Burnley), S Davis (Southampton), O Norwood (Huddersfield), S Ferguson (Newcastle), C Evans (Blackburn), S Clingan (Kilmarnock), J Steele (New York Red Bulls), P Paton (Dundee United), N McGinn (Aberdeen), B McKay (Inverness), M Paterson (Huddersfield), J Ward (Derby), D Shiels (Rangers), J Magennis (Aberdeen).