O'Callaghan, who celebrated his 24th birthday last Monday, will partner Jeremy Davidson who has been nominated to lead the side and other Munster players in the A squad include, Anthony Horgan, James Blaney and Mick O'Driscoll, while there is also a first time call up for Mike Prendergast.
Neither Rob Henderson (ankle) nor Jeremy Staunton (groin) were considered beause of the injuries they carry and there is still no place in the second string for Mike Mullins.
The Irish A team to play England A in Donnybrook, on Friday, March 28th at 19.00hrs is;
15 Gordon Darcy (Leinster/Lansdowne) 14 James Topping (Ulster/Ballymena) 13 Gavin Duffy (Connacht/Galwegians) 12 David Quinlan (Leinster/Blackrock College) 11 Tyrone Howe (Ulster/Dungannon) 10 Barry Everitt (London Irish) 9 Brian O Meara (Leinster/ Cork Constitution) 1 Emmett Byrne (Leinster/St.Mary s College) 2 Paul Shields (Ulster/Ballymena) 3 Simon Best (Ulster/Belfast Harlequins) 4 Donnacha O Callaghan (Munster/Cork Constitution) 5 -Jeremy Davidson (Ulster/Dungannon) captain 6 Simon Easterby (Llanelli) 7 Kieron Dawson (London Irish) 8 Des Dillon (Leinster/UCD).
Replacements: 16 James Blaney (Munster/Shannon) 17 Peter Bracken (Connacht/Galwegians) 18 Mick O Driscoll (Munster/ Cork Constitution) 19 Aidan McCullen (Leinster/Lansdowne) 20 Michael Prendergast (Munster/Young Munster) 21 Mark McHugh (Connacht/St.Mary s College) 22 Anthony Horgan (Munster/Cork Constitution).