However, the Ospreys will start as favourites after they knocked Alan Gaffney's side out of the Anglo-Welsh Cup. Now they have set their sights on European glory.
Hook's team have made it to the final eight of the Heineken Cup for the first time in their history, and are in a rich vein of form that saw them thrash Ulster 32-7 last weekend.
And with Wales's Grand Slam success under his belt, Hook has not played in a losing team since the December 27th defeat to the Scarlets.
"It's a remarkable run and we don't want it to stop," Hook told BBC Sport. "Success has been building from the regions into the national side, and long may that continue.
"Saracens will be a huge game, you realise how important it is when you see how excited the boys are in training."
Saracens: B Russell; R Haughton, K Sorrell, A Farrell, K Ratuvou; G Jackson, N de Kock (Capt); N Lloyd, M Cairns, C Visagie, H Vyvyan, K Chesney, P Gustard, R Hill, B Skirving
Replacements: F Ongaro, C Johnston, T Ryder, D Barrell, M Rauluni, A Powell, F Leonelli
Ospreys: L Byrne; J Vaughton, S Parker, G Henson, S Williams; J Hook, J Marshall; D Jones, H Bennett, A Jones, I Gough, A-W Jones, J Thomas, M Holah, R Jones (Capt)
Replacements: R Hibbard, P James, I Evans, F Tiatia, R Webb, A Bishop, A Brew
Referee: Alan Lewis (Ireland)