"We could have played all three but, with such an important period coming up, we didn't feel it was worth risking any further damage," says the Warriors director of rugby.
Ryan Powell comes in to the starting line-up at scrum-half, while Mark Tucker moves to centre alongside Gary Trueman and is replaced on the wing by Thinus Delport. Tevita Taumoepeau steps into Horsman's shoes, with Ireland U21 international Callum Black providing front-row cover.
Tom Harding joins the forward replacements, while Simon Whatling is also on the bench after Thomas Lombard aggravated the hamstring injury that kept him out of the Wasps game. With Delport now starting the game, Lee Best also joins the 22.
Team: 01 Darren Morris; 02 Chris Fortey; 03 Tevita Taumoepeau; 04 Craig Gillies; 05 Tim Collier; 06 Drew Hickey; 07 Pat Sanderson (c); 08 Kai Horstmann; 09 Ryan Powell; 10 James Brown; 11 Marcel Garvey; 12 Gary Trueman; 13 Mark Tucker; 14 Thinus Delport; 15 Shane Drahm
Replacements: 16 Callum Black; 17 Aleki Lutui; 18 Will Bowley; 19 Gavin Quinnell; 20 Tom Harding; 21 Simon Whatling; 22 Lee Best