Tour manager Gerald Davies said: "The Lions' next challenge is the Southern Kings at the new Nelson Mandela Bay Stadium in Port Elizabeth. The match will be played on Youth Day tomorrow which is a National Holiday.
"We are honoured to be playing on such a special day and I know the Lions are looking forward to the match and maintaining the unbeaten tour record."
Commenting on the team selection, head coach Ian McGeechan said: "This is Test week and there is a noticeable change in attitude within the touring party.
"We are now heading towards the business end of the tour and the reason why we have come to South Africa.
"As you would expect the immediate focus is the next match against the Southern Kings on Tuesday before attention turns to selection for the first Test for which all players will be considered.
"The Southern Kings is not a regular team but we understand there are some very talented players in the squad for the match.
"Experience tells me that you can never underestimate any South African team and like the other teams we have faced on the tour so far we will not take them lightly.
"Seven players are backing up from the Western Province match with Nathan Hines, Joe Worsley, Riki Flutey and Keith Earls given the opportunity in the starting line-up in different positions.
"The team will be captained by proud Munster man Donncha O'Callaghan, an experienced Lions tourist, who is a very popular member of the squad.
"This will be his tenth Lions match including two Tests against New Zealand during the 2005 tour.
"As mentioned by doctor Gary O'Driscoll yesterday at our medical briefing, we will give Mike Blair a fitness test on Tuesday morning.
"He had to withdraw from the replacements bench against Western Province last Saturday due to a foot injury."
Meanwhile, some hours after the team announcement, it was confirmed that Tommy Bowe will join the Lions squad for the game in Port Elizabeth as a precautionary measure as Shane Williams is suffering from a mild tummy bug.
A further update will be issued on the morning of the game.
BRITISH & IRISH LIONS TEAM/REPLACEMENTS (v Southern Kings, 2009 Lions Tour, Tuesday, June 16, Nelson Mandela Bay Stadium, kick-off 3pm local time/2pm Irish time):
15. Keith Earls (Munster/Ireland)
14. Shane Williams (Ospreys/Wales)
13. Riki Flutey (London Wasps/England)
12. Gordon D'Arcy (Leinster/Ireland)
11. Luke Fitzgerald (Leinster/Ireland)
10. James Hook (Ospreys/Wales)
9. Mike Blair (Edinburgh/Scotland)
1. Andrew Sheridan (Sale Sharks/England)
2. Ross Ford (Edinburgh/Scotland)
3. Euan Murray (Northampton Saints/Scotland)
4. Simon Shaw (London Wasps/England)
5. Donncha O'Callaghan (Munster/Ireland) (capt)
6. Nathan Hines (Perpignan/Scotland)
7. Joe Worsley (London Wasps/England)
8. Andy Powell (Cardiff Blues/Wales)
16. Matthew Rees (Scarlets/Wales)
17. Adam Jones (Ospreys/Wales)
18. Tom Croft (Leicester Tigers/England)
19. David Wallace (Munster/Ireland)
20. Harry Ellis (Leicester Tigers/England)
21. Ronan O'Gara (Munster/Ireland)
22. Ugo Monye (Harlequins/England)