Peter Murchie admits Glasgow's January schedule could make or break their season.
The Warriors have already ticked off part one after reigniting their bid for the Guinness PRO12 play-offs with Saturday's 29-15 win over Cardiff.
But now the Scotstoun outfit turn their attentions to their two remaining Champions Cup pool clashes with Munster and Leicester.
Gregor Townsend's side sit second in Pool 1, three points behind the Irishmen - who they face at home on Saturday - but five ahead of the big-spending Tigers.
Victory in both matches will guarantee the Scots a place in the quarter-finals for the first time in the club's history - but anything less could leave them staring at another European failure.
Murchie said: "We looked at the three-week period starting with Cardiff and ending with the two Champions Cup matches and said it could totally decide the end to our season.
"If we hadn't beaten Cardiff we'd have been under massive pressure in the PRO12.
"Now with these next two games we've got a chance to qualify from our group. If we beat Munster then Leicester, we'll make the quarters.
"There's not many times we've been in this position. We've talked about doing it for so long but now the boys are just so determined to make it happen this year."
But Murchie admits his side will have to top the performances they put in while shooting down French champions Racing 92 twice last month if they are to see off Rassie Erasmus's Red Army this weekend.
"It's a massive game," said the full-back. "We've played them twice already this season and lost both times.
"We know how big the game is and that they'll come flying out at us. We've got to be more up for it than them. It's going to take our best performance of the season."
Murchie, 31, deputised for the rested Stuart Hogg against Blues and made his mark with a try double.
Hogg should return against Munster but Murchie will not give up his jersey without a fight.
He said: "Stuart is a great player so when you get an opportunity, you've got to play well.
"If you don't, you're probably not going to get to stay in the next week.
"We've got enough guys that we can swap things and change it round, so if you don't take your chance you'll miss out.
"I want to play in a successful team and do myself justice. I love playing for this club so it was good to get a win and make my mark at the weekend."
However, Murchie is certain to get a prolonged run in the team once the RBS 6 Nations kicks off next month.
But the Englishman admits he and the other players who miss out on international selection will have to do better than they faired during the autumn Test series, where Glasgow suffered three damaging PRO12 defeats on the bounce.
Things have picked up since, with Warriors racking up their fifth-straight win against Cardiff.
However, Murchie warned: "If we go back to the period during the November Tests, we didn't play well enough, so this time, there is a big onus on us.
"In the past, we've made the top four because the guys left behind won games during international periods.
"So we'll have to play better come the Six Nations than we managed in November. But there are boys champing at the bit who want to play and hopefully that will help us win games."