Glasgow head into the last home game of their regular league campaign in third place following their defeat in Wales last weekend, four points behind leaders Ulster and five ahead of Scarlets, who are just outside the play-off places.
Townsend said: "It's a huge game for the club, even more so after our defeat to the Scarlets last week. We expect a reaction from our players.There have been a lot of memorable moments at Scotstoun this season and this has the potential to be another great game."
He added: "We're really respectful of our opponents, they take a combative approach to every game, they challenge at the breakdown, have an excellent set piece and are ranked as the best defensive team in the competition.
"It's a wonderful challenge for our players - going up against a top quality side in front of their home support."
John Barclay will start on his 150th appearance for Glasgow, and possibly his last home game before his summer departure, while centre Graeme Morrison also starts.
Townsend said: "A number of players have been given the opportunity to represent the club in such an important fixture and it's worth highlighting the inclusion of Graeme Morrison, who has been a tremendous servant for the club over the past 10 years.
"He has had injury issues this season, but he's been training really well in recent weeks and we're delighted to have him back in the team.
"It's great for Graeme to line up alongside his good friend John Barclay, who we know will be playing what could be his final home game for the club on his 150th appearance, which is a tremendous achievement."
Sean Lamont, Alex Dunbar, Duncan Weir and Niko Matawalu are among the others returning to the starting line-up.
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