Nothnagel captained the side earlier in the season and since returning from injury has been a key player in their wins over Benetton and Racing 92 over the past two games.
Ruan Delport comes into the side for him, and will provide cover, with Ruben Schoeman returning to the squad for the trip to Glasgow for Saturday’s knockout game.
Steam Pienaar and Jarod Cairns have been added to the matchday 23 for the trip, while Jaco Kriel also returns to add a lot of experience to the side for the fixture.
The team will be captained by Marius Louw, who scored a brace of tries in the win over Racing 92 on Saturday.
Emmanuel Tshituka, who was red-carded early in the game, misses out on the trip as he serves a three-game suspension for the red card.
Emirates Lions touring squad
Forwards:
JP Smith, Rynhardt Rijnsburger, PJ Botha, Morne Brandon, Asenathi Ntlabakanye, Ruan Dreyer, Willem Alberts, Ruan Delport, Ruben Schoeman, Travis Gordon, Jaco Kriel, Jarod Cairns, Ruan Venter, Francke Horn.
Backs:
Sanele Nohamba, Morne van den Berg, Gianni Lombard, Edwill van der Merwe, Marius Louw (captain), Mannie Rass, Rynhardt Jonker, Rabz Maxwane, Quan Horn, Andries Coetzee, Steam Pienaar.