The head coach has challenged his team to attack their latest Heineken Cup match with pace and intensity as they seek a first win in this years’ competition.
He told glasgowwarriors.org: “It would be a great achievement to go out and win in France, but we’ve selected a team capable of playing a high-tempo game, which is what we’ll need to do in order to beat Castres.
"We have some very dangerous runners in the backline, five of whom have played on the wing this season. There is pace throughout the side and I’m also looking for a hard edge from the forwards over at Stade Pierre-Antoine.
“We must be much improved in our accuracy from last week’s performance, which was well below the standards we demand of each other. It wasn’t a true reflection of what this group has produced this season.
"Castres grew in confidence the more we failed to hold on to ball and were as strong in the set-piece as we predicted they would be. They will be even better at home, but I expect to see a very different performance from us on Sunday.”
John Barclay will skipper the team and will start in the back-row alongside James Eddie at blind-side with Ryan Wilson at number 8; Moray Low begins the game at tight-head prop with Gordon Reid on the other side of hooker Pat MacArthur. It’s the first game this season that won’t feature Michael Cusack who is unavailable due to a shoulder injury.
Tom Ryder, who has just signed a new contract to keep him at the Warriors until at least May 2015, will partner Tim Swinson in the second-row.
The changes continue into the back line with Sean Maitland involved from the start in the no.15 jersey.
Sean Lamont moves in one from his usual spot on the wing and will, on his fiftieth appearance for the Warriors, occupy the outside centre position with Peter Horne, impressive in the last two outings, retaining his spot at number 12.
Ruaridh Jackson is recalled to the stand-off position with Nikola Matawalu also earning the nod to start at scrum-half. DTH van der Merwe – also making his fiftieth appearance in a Warriors shirt - and Tommy Seymour, the clubs two leading try scorers take up the wing positions.
There is a mix of youth and experience ready to take to the fray off the bench with Dougie Hall, Ryan Grant and Rob Harley alongside Elite Development players George Hunter and Nick Campbell covering the forwards. Also in the substitutes are Sean Kennedy, the EDP scrum-half, Byron McGuigan and Graeme Morrison who is set to make a welcome return from injury.
Gregor continued: “This is just one in a big series of games we’re involved in over the next few weeks and we need to be at our best in each of these encounters.
“This weekend gives us an opportunity to perform and produce a rare win in France but do that we need to be sharper, more accurate and get back to scoring tries.”
14 Tommy Seymour
13 Sean Lamont
12 Peter Horne
11 DTH van der Merwe
10 Ruaridh Jackson
9 Nikola Matawalu
1 Gordon Reid
2 Pat MacArthur
3 Moray Low
4 Tim Swinson
5 Tom Ryder
6 James Eddie
7 John Barclay (Captain)
8 Ryan Wilson
Substitutes
16 Dougie Hall
17 Ryan Grant
18 George Hunter
19 Nick Campbell
20 Robert Harley
21 Sean Kennedy
22 Byron McGuigan
23 Graeme Morrison