It is all a measure of the progress the 24-year-old has made in the domestic game in the 18 months since he was plucked from obscurity, having been a peripheral figure in the Ulster squad before being brought across the Irish Sea to his mother's home city.
It also exemplifies the transformation in Glasgow's spending power this year which has allowed them to bring the Lamont brothers, Sean and Rory, back to the club, as well as being able to recruit Sean Maitland from Canterbury Crusaders and Niko Matawalu, the Fijian scrum-half who has played Test rugby in the back three.
Indeed, there may now be greater strength in depth in that department at Glasgow than at any club in Europe since no fewer than 11 different players have started at full-back or wing for the club this season, even though Rory Lamont – he is expected to be back in action shortly for the first time this season – has been in rehab.
That is almost twice as many as their inter-city rivals Edinburgh yet, for all their options, Glasgow have so far struggled to generate the sort of finishing power they would expect to achieve with such talent at their disposal.
Seymour and DTH van der Merwe, a player who was just as unknown in top-flight professional rugby when he was brought to Warriors, have been far and away the most effective of those players, topping the club's scoring charts with five apiece, yet they have started only four of Glasgow's 14 matches together.
Explaining his decision to sign the new deal that will keep him in Glasgow at least until 2015, Seymour expressed confidence in what is happening at the club. "It's an exciting place to be at the moment and, even though the results don't always go your way, we know we're heading in the right direction," he said.
"The way the squad and team are developing is a massive factor in staying on because the players and coaches here do believe that we're building towards something special."
That may be so, but the statistical evidence is to the contrary.
The price paid by John Barclay, the stand-in captain, for scoring the club's first try in more than a month's play almost seemed to sum up how hard they are finding it to score points this season, the international flanker having suffered a worrying-looking hamstring injury as he strove to get over the line in Castres on Sunday.
That try was not enough to prevent Glasgow from suffering a fourth straight defeat in the Heineken Cup, matching Edinburgh's run of failure in the competition this season, so Seymour rightly acknowledged that the forthcoming derby meetings between the two, the first of which takes place at Scotstoun on Friday, have particular significance this season.
"The game against Edinburgh this Friday at Scotstoun is massive for us as a club, not just because of the intensity of the rivalry, but for our season and for our position in the league it's vital we do everything we can to pick up points."
With Glasgow having slipped out of the play-off places in the RaboDirect Pro12 it now looks as if – setting aside their desire to win the 1872 Challenge Cup – both Scottish teams have to win both derbies if they are to have a realistic chance of playing any knockout rugby this season.
As important as they are collectively, the chance to impress individually when directly up against potential international rivals can be a huge motivation for those eligible to play for Scotland and that now very definitely applies to Seymour.
These matches have the potential to pit him head to head with Tim Visser, the Dutch-born naturalised Scot who is comfortably clear in his bid to finish the season at the top of the Pro12 try-scoring charts for the fourth successive season.
"I said when I joined Glasgow that it was a little like coming home because of the family connection and I'm really settled here," he said. "I came here to play regular rugby and to get that call-up to the Scotland squad was a real vindication of the hard work though I know, given the talent that is now in the Warriors squad, that I have to keep at it and keep trying to get better."