Sitting in tenth on the URC table, every match is a crunch match for the Sharks if they want to make the playoffs. Head coach JP Pietersen has had no hesitation in handing the talented 18-year-old Siyaya a first start, while also welcoming back several stalwarts.
The Tshituka brothers both start, while Springbok Jaden Hendrikse and Jean Smith will feed the potent backline, which has Boks Ethan Hooker and Edwill van der Merwe on the wings.
Meanwhile, there are heavy hitters on the bench in World Cup winners Ox Nche and Vincent Koch.
"The mood in the camp is really good," said captain Andre Esterhuizen.
"We know we're building something here and we know we basically need to win four out of four games to stand a chance to get into the top 8. The group is really motivated, we've had good chats, good training sessions and we're looking forward to the challenge ahead.
"We haven't been the best on the road this year, but that's something we're looking to rectify. We know we can play, we have the squad to do that and it's about doing that every single weekend."
Esterhuizen pointed out that the key message for the team is about consistency, because "That's something we've lacked this season. We're driving consistency in performance and we know if we perform well, we have a good chance of winning these matches. It's a mindset thing, you need to be switched on for every game, because this is a tough competition and you can lose at any point if you aren't at your best every game."
Looking at Ospreys, he warns that this match is going to be every bit as tough as any URC clash the team will face.
"They're a tough side, especially at home," he continued.
"They play a lot of rugby, they're physical, they have a nice attacking style of rugby and they're a side that likes to move the ball around, so we're looking forward to that challenge."
Sharks - 15 Zekhethelo Siyaya, 14 Edwill van der Merwe, 13 Le Roux Malan, 12 Andre Esterhuizen (c), 11 Ethan Hooker, 10 Jean Smith, 9 Jaden Hendrikse, 8 Manu Tshituka, 7 Vincent Tshituka, 6 Phepsi Buthelezi, 5 Emile van Heerden, 4 Jason Jenkins, 3 Hanro Jacobs, 2 Fez Mbatha, 1 Phatu Ganyane.
Replacements: 16 Eduan Swart, 17 Ox Nche, 18 Vincent Koch, 19 Corne Rahl, 20 Nick Hatton, 21 Bradley Davids, 22 Siya Masuku, 23 Jurenzo Julius.