Warriors will be bidding for their first league win of the season after crucial lineout errors cost them the opportunity of breaking their duck against fellow-strugglers Northampton Saints at Sixways last Saturday.
The squad is also boosted by the availability of tight-head prop Chris Horsman, who is not among Wales head coach Gareth Jenkins' 22 for the international clash with Canada this weekend.
"We must thank Gareth for being understanding and releasing Chris," says John Brain. "He'll start on the bench."
Of the Quins match, Brain knows what Warriors must produce.
"In terms of going forward, we're looking to bring about an improvement in our set phase and lineout in particular. We need to improve defensively and become a difficult team to beat."
The mood in the dressing room is "as good as it can be in the circumstances", he adds.
"We all know that, if we manage to cross that bridge and achieve a win, it could kick-start us. The teams near the bottom of the table are a couple of wins away from getting back in the mix. We all know that that's possible, and we have to achieve it. We have an opportunity to do that tomorrow."
Team: 01 Lee Fortey, 02 Ben Gotting, 03 Darren Morris, 04 Craig Gillies, 05 Tim Collier, 06 Kai Hortsmann (c), 07 Tom Harding, 08 Drew Hickey, 09 Ryan Powell, 10 Shane Drahm, 11 Mark Tucker, 12 Thomas Lombard, 13 Dale Rasmussen, 14 Thinus Delport, 15 Lee Best
Replacement: 16 Chris Horsman, 17 Chris Fortey, 18 Phil Murphy, 19 Gavin Quinnell, 20 Matt Powell, 21 James Brown, 22 Aisea Havili