The Guinness PRO14 Round 8 tie, Ulster’s first ever competitive fixture on South African soil, will be televised live on BBC2 NI.
Gilroy, who scored two tries on his senior debut against Cardiff Blues back in November 2010, has not featured for Les Kiss’ side this season after picking up a back injury during pre-season.
Chris Henry will captain the team for the historic fixture and he will be joined in the back row by Sean Reidy and Matty Rea, who will be making his 7th appearance of the season.
Andy Warwick, John Andrew and Wiehahn Herbst make up the front row, while Kieran Treadwell, a member of Ireland’s squad for the November Series, is paired with Al O’Connor in the second row.
John Cooney has recovered from injury to partner Christian Lealiifano at half back, with Darren Cave and Louis Ludik combining in midfield.
Gilroy is joined in the back three by Charles Piutau and Andrew Trimble, who became Ulster’s most capped player a fortnight ago versus La Rochelle.
Scrumhalf Jonny Stewart – a debutant in the game against Leinster at the weekend – is named among the replacements along with fellow Abbey Insurance Academy player Adam McBurney (hooker).
Callum Black, Ross Kane, Robbie Diack and Clive Ross are the forwards in reserve, while Peter Nelson and Tommy Bowe are the additional backline options for Kiss.
Ulster Rugby team to play Southern Kings, Saturday 4th November, Wolfson Stadium, 3.00pm local (1.00pm UK/Irish time):
(1-8): Andy Warwick, John Andrew, Wiehahn Herbst, Kieran Treadwell, Alan O’Connor, Matty Rea, Chris Henry (captain), Sean Reidy;
(9-15): John Cooney, Christian Lealiifano, Andrew Trimble, Darren Cave, Louis Ludik, Craig Gilroy, Charles Piutau.
Replacements (16-23): Adam McBurney, Callum Black, Ross Kane, Robbie Diack, Clive Ross, Jonny Stewart, Peter Nelson, Tommy Bowe.