The Cherry and Whites led at half time at Quins last Saturday evening and also for the majority of the second half until a wicked bouncing ball just minutes from full time allowed the hosts to pounce for the winning score.
Toulouse currently lead the pool but, with Harlequins breathing down their necks, need to a win to clinch top spot.
Gloucester can't qualify for the knock out stages but have been more than competitive in this group and were only denied a famous victory in the first meeting between these two teams by a controversial late score.
Talking to the media ahead of the game, Redpath admitted that it's been small margins that have cost his team in Europe this year.
"Toulouse and Quins away, we could have had several more points in the bag. They're small margins. We put in a very good performance at Toulouse and lost to a try seven minutes from time."
"Last weekend, we played pretty well. They (Quins) had two opportunities and the ball bounced badly for us and they capitalised on them."
"I can't fault the players' effort, it's just been one or two little things that have let us down. Some things you can't control. But you can't let these things get you down, you have to keep plugging away.
And he admitted that Friday evening is a huge challenge but one to really savour.
"But to bring Toulouse back to Kingsholm on a Friday night is probably one of the biggest games you'll get in club rugby for a Gloucester player.
"It's a great opportunity for our players to go toe to toe with one of the very top teams in Europe. It's a reputation game and a chance to shine."
Jonny May; Charlie Sharples, Mike Tindall, Eliota Fuimaono-Sapolu, James Simpson-Daniel; Freddie Burns, Rory Lawson; Nick Wood, Scott Lawson, Rupert Harden; Jim Hamilton, Alex Brown; Alasdair Stroskoch, Akapusi Qera, Luke Narraway (capt)
Darren Dawidiuk, Dan Murphy, Shaun Knight, Will James, Matt Cox, Dave Lewis, Ryan Mills, Henry Trinder