Gregor Townsend, their head coach, admitted as much yesterday as he named a side showing six changes to that which destroyed Newport-Gwent Dragons in the knowledge that Ulster faced an even more drastic overhaul of their side after a rather less convincing defeat of winless Zebre.
"In terms of fixtures as well [as the occasion] we're now playing six out of the seven top teams in our last seven games. We're playing a team that's beaten us three times this year and are top and if ever we've got a chance of narrowing the gap between Ulster and ourselves, it's this weekend," Townsend acknowledged.
Ulster have made a dozen changes, 11 personnel and one positional. Since they already had some serious injury issues, as well as players unavailable because of Ireland calls last week, it is clear their resources are being stretched to the limit at a time when Glasgow's depth is stronger than ever before.
Townsend was therefore encouraged to take a calculated gamble for this vital fixture by leaving Scott Wight, one of his established stand-offs, on the bench in favour of Peter Horne, who would have made a Test debut at inside centre a month ago had he not suffered a thumb injury.
The 23-year-old has never worn the No.10 jersey for Glasgow, but made a spectacular cameo appearance in the role against Northampton last month with a stunning solo try.
"It's a great memory for him and the club, scoring that try against Northampton," said Townsend. "He's a player that can play at 12 and 10. He's got the kicking and the handling ability to be a first receiver and I felt that with him coming back from the Scotland camp this week – and I know they left that decision quite late until they announced it to the players – to give him an opportunity to start. Scott's been doing really well at training so he provides security at 10 and we've got 10 covered very well."
Since first making his mark as a schoolboy helping Bell Baxter become the only state school in the last 16 years to win the Scottish Schools Cup, Horne went on to prove himself as a goalkicker when Scotland Under-20s won all three of their home games in 2009. It has taken him time to come through at the top level, but his selection in this role for such an important game, so soon after that near miss at Test level, indicates he is ready for new responsibility. That came through in the way he expressed due respect for tonight's visitors, but also confidence in himself and his team-mates as he considered the task ahead.
"We have seen the Ulster team and they have some big names in there, but also a lot of young guys who you cannot underestimate. Look at [Stuart] Hogg and [Mark] Bennett; they are only young but are two of the most exciting prospects in our game so I'm sure that those boys will be just the same. They will be enthusiastic to put their marker down. I hope we can put a lid on it and make sure we have a good, strong squad performance and bring home the W," he said.
"We have a fantastic squad, we have shown that over the last couple of weeks. The guys coming in have done fantastically well and we are really going to target this game. There are guys who are itching to get the jersey back on and make sure that the national team guys, when they come back, have a pretty tough time getting back into the squad."
It certainly looks that way with Graeme Morrison, for many years the defensive coordinator in Glasgow's back-line, still unable to force his way back into the side in spite of Horne's switch from the inside centre role.
Instead, the relatively unheralded Alex Dunbar partners the latest boy wonder, Bennett, in midfield, the pair each having been among the scorers in Newport.
Last weekend was about turning on the style; tonight Glasgow have a real chance to show they have the substance of potential champions.