Kick-off is at 16:30.
Van der Merwe joined the Blue Bulls from the Cheetahs last year, but has since been recovering from a knee operation.
The team also includes a number of Junior Springboks who recently participated in the Junior World Championship in France, while centre Francois Venter also makes a comeback after a groin operation.
The game forms part of the Lions' preparations for their Super Rugby promotion-relegation series against the Kings on the weekends of July 26 and August 2.
Teams:
Blue Bulls:
15 Clayton Blommetjies, 14 Jesse Kriel, 13 Ulrich Beyers, 12 Francois Venter, 11 Travis Ismaiel, 10 Handrè Pollard, 9 Rudy Paige, 8 Jean Cook, 7 Jacques du Plessis, 6 Shaun Adendorff, 5 Dennis Visser, 4 Schalk van Heerden, 3 Marcel van der Merwe, 2 Willie Wepener, 1 Dawie Steyn
Substitutes: 16 Bongi Mbonambi, 17 Hencus van Wyk, 18 Christof Gouws, 19 Irne Herbst, 20 Roelof Smit, 21 Ruan Snyman, 22 Tony Jantjies, 23 Dries Swanepoel, 24 Rohan Janse van Rensburg
Lions:
TBA
Lions Challenge fixture list for 2013:
January 19: Lions 51-13 Russia
January 23: Lions 33-17 Cheetahs
February 2: Lions 33-38 Bulls
February 9: Lions 41-31 Kings
February 23: Namibia v Lions - Cancelled
March 16: Lions 56-24 Mont de Marsan
April 13: US Invitational v Lions - Cancelled
April 20: US Invitational v Lions - Cancelled
April 27: Chicago Lions v Lions - Cancelled
May 11: Lions v Agen - Ellis Park - Cancelled
June 1: Lions 74-14 Samoa - Ellis Park
June 14: Lions 42-12 Western Province - Ellis Park
June 21: Lions 33-29 Sharks - Ellis Park
July 6: Lions v Blue Bulls - Loftus Versfeld - 16:30
July 13: Lions v Griquas - Ellis Park - 15:00
July 26: Super Rugby promotion/relegation - TBA - 19:10
August 2: Super Rugby promotion/relegation - Ellis Park - 19:10