Nothing could say more about the current Glasgow Warriors management team’s confidence in its own methods and abilities than the omission on Ryan Wilson, one of the club’s co-captains for their most important match of the season so far.

Win in Lyon and their chances of reaching the Champions Cup quarter-finals for only the second time in the 24 year history of the competition improve exponentially. Leaving out of the squad a player who was in Scotland’s 23 for every match of the autumn Test series, in favour of both Adam Ashe, who trained with Scotland during the autumn but has not played for the national side since 2015 and Chris Fusaro, who won the last of his four caps the year before that, is consequently telling.

Dave Rennie, Glasgow’s head coach, has always said Glasgow teams will be selected on what the management sees rather than reputations and, big as the gulf can be between the Test arena and Pro14 matches during international windows, a bold looking call has been made on that basis.

“Adam Ashe has been outstanding for us over the last few weeks. We were obviously keen to bring Matt Fagerson back in and both those boys have really good footwork, gives us very good go-forwards and carry, are explosive and defend really well. We just really wanted to reward that... it’s based on form. Ryan’s played pretty well for Scotland as well, but we know that within those loose forwards they’ll have to share the load and we wanted a specialist seven on the bench in Chris Fusaro knowing that Rob Harley can move from lock to 6 if we have a couple of injuries. So, unfortunately, Ryan misses out this week but as captain he’s been outstanding, he’s contributed massively to the preparation and I’ve been really impressed by him.

“We wanted to reward guys not just for playing well over the last month for us but there’s a number who played really well leading into the international window and played well for Scotland. We had a lot of discussions around the loose forward mix and we’re happy with what we came up with and we’d have been more than happy if Ryan had started.”

The other obvious example is in midfield where Nick Grigg another who trained with Scotland in November without making an appearance, is preferred to Huw Jones, who started the three toughest Tests in spite of match-costing defensive errors in the first against Wales.

Again, Rennie explained that it was simply a selection matter, Grigg’s form in recent weeks having made it impossible to leave the little tyro out.

“He’s been outstanding, both sides of the ball,” Rennie praised. “His ability to chop defensively, his ability to carry, he has so many line breaks and tackle breaks and his work beyond the attack, at post-tackle he’s won a lot of ball. He’s done everything we’ve asked of him and deserves another crack.”

There is an awareness that a combination of French opposition and conditions in Lyon will make this a different sort of challenge from playing a top of the ground game in the Pro14 and even in Test matches in Cardiff and Edinburgh and while Rennie reckoned it would have been a mistake to take too much out of players’ legs by training on boggy surfaces all week, they have prepared with that in mind.

“Obviously, we play on a hard, fast surface here and I don’t think we will get that at Lyon.. They are a big side, very skilful, so we still want to play a game that is quick, but we will have to bring a high level of physicality to get the ball we want. We’ve picked a side that we think can do that,” he said. “We are mindful that they offload more than any side in the competition. They have some unbelievable athletes. Charlie Ngatai, who I’ve had a lot to do with over the last five or six years, is a high-quality player, a world-class midfielder. We’re clear on what we need to do and on the threats they bring. The challenge is being good enough to expose them. We have trained in Scottish weather, which is probably a good start. The forwards trained on grass for scrummaging, but we haven’t trained on grass all week. We didn’t want to go there with heavy legs after training in mud. We are conscious of the fact that conditions will be a bit different, but you just have to deal with it.”

While he believes they have addressed the failings that have consistently let them down in Europe down the years, Rennie knows this will be a crucial test of that.

“Hopefully we have shown evidence of the learnings that we got from last year,” he said.“Our ability to look after the ball has been a massive focus for us, as has our ability to go multi-phase. There was good evidence of that last week.

You need to have a strong set-piece so we have worked really hard and Jon Humphreys has done a great job around our maul and our scrum. To be competitive in this competition you need to be strong up front.

“Then it’s about being accurate and relentless in our attack. I think we have defended a lot better in. I think we can be better still, but denying opportunities to the opposition is massive.

“Our discipline has been excellent. The penalty count last weekend was 17-6 and we’ve had a string of games where we have been penalised less than 10 times. That’s important against the big sides who can put you in the corner and hurt you. Were happy with the shifts we’ve made in those areas.”