Three for Thursday: Why Seattle Sounders vs. Real Salt Lake could be biggest game of the year

A few months ago, I wrote about why Seattle-RSL was one of the most underrated rivalries in the league, and I'm sticking by my guns, especially with the two teams now sitting in first and second places in the Supporters' Shield race.

That alone is enough to make Friday night's clash between the two teams at CenturyLink Field (10 pm ET, NBCSN), a mouthwatering prospect for MLS fans. But is it the best regular-season game left on the calendar? I say yes, and here's why:

We may finally get to see Seattle's vaunted front four

Much of the buzz in Seattle after Clint Dempsey's arrival has not just been about the signing of one of the best American players of his generation, but the potential an already dangerous Sounders offensive core could now boast with Dempsey in the fold.

Unfortunately, we have not been able to see the like of Dempsey, Obafemi Martins, Eddie Johnson and Lamar Neagle in action due to a combination of injuries and international absences. On Friday, with Dempsey and Johnson returned from US duty, folks may finally get that chance and against one of the best teams in the league, to boot.

Of course RSL, welcoming back Nick Rimando and Kyle Beckerman (though without Álvaro Saborío) may have something to say about that. But whatever the final outcome, it will be a joy for fans across the league to see that accumulation of talent play for 90 minutes.

A true test of RSL's Supporters' Shield credentials (as well as Seattle's)

It wasn't long ago that Seattle looked done and dusted in the Supporters' Shield race and RSL looked poised to run away with it. Nowadays, it could scarcely be much closer.

Heading into this weekend's action, RSL hold the points lead, with a two-point edge over the Sounders in the Shield race, though Seattle have a superior points per game number at 1.77 to RSL's 1.71. However, despite Seattle's superior PPG, they have a much harder run-in, including two games against LA, than RSL's.

Nonetheless, whichever team wins this contest will be very well-poised to break open one of the closest Supporters' Shield races in recent memory. Given the rest of their schedule, it would be hard to see RSL dropping the lead they'd extend with a win.

Seattle, on the other hand will have plenty of momentum and confidence on their side with plenty of opportunities to build on it, especially should that much-talked about attack click on Friday night.

Another chapter in two proud legacies

We may be seeing the most successful iterations yet of two of the most consistenly successful teams of the last few years.

For RSL, the game in Seattle is a chance to become the first team in the post-shootout era to achieve the 15-win, 50-point mark for four consecutive seasons (though the Galaxy can join them with seven more points/two wins in their final seven games).

Think about all those great teams, and consider that this one, pushing for the Shield, might be the best one yet in what many considered a rebuilding season. A win here, and the season sweep of the Sounders that would come with it, would go a long way towards confirming this RSL team's status as one of the best in franchise history.

For Seattle, their 1.77 points per game clip is shy of the 1.85 mark they put up in 2011, but a win Friday night will put them up to 1.81, and another couple wins in the home stretch will easily put them up there among the best regular-season Sounders teams. It would also put them in pole position to win a first-ever Supporters' Shield.

A seminal moment in franchise history? Maybe not, considering US Open Cup, CCL and playoff exploits, but it's pretty darn close.