"Five Things" is a season-long series presented by the Children's Mercy Sports Medicine Center that highlights the top storylines and players to watch ahead of each match. To visit the series archive, click here.

Arguably the most consequential match of the 2021 MLS regular season to date will unfold Sunday night when second-place Sporting Kansas City (8-3-3, 27 points) visits first-place Seattle Sounders FC (9-1-5, 32 points) in a titanic Western Conference clash at Lumen Field.

Supporters can catch Sunday's highly anticipated encounter live on Bally Sports Kansas City, Bally Sports Midwest, BallySports.com and the Bally Sports app with three hours of live coverage beginning at 7:30 p.m. CT. The contest will also air live locally on Sports Radio 810 WHB and La Grande 1340 AM.

Sporting and Seattle have been two of Major League Soccer's most impressive sides through the first three months of the 2021 campaign and are slated to meet on three occasions over the next three months. Needless to say, Sunday's battle could prove to be a huge tone setter as both clubs continue the race for first place in the wild West.

With plenty to be excited about this weekend, we examine five major storylines surrounding the matchup in the space below.

1. Battle of the Best

Two of the top three teams in the Supporters’ Shield table will lock horns on Sunday. Led by two-time MLS Cup champion head coach Brian Schmetzer, Seattle sits at the summit with 32 points and a formidable 9-1-5 record. Five points behind—and with a game in hand—are Sporting, who will enter the game with every intention of giving the mighty Sounders their first home defeat of the season.

Boasting one of the best attacks in MLS, Sporting has ridden the coattails of Daniel Salloi, Alan Pulido and Gianluca Busio while also receiving boosts from savvy center back pairing Andreu Fontas and Ilie Sanchez. The Sounders, meanwhile, have seen Raul Ruidiaz light up the league with 11 goals and additional contributions from playmaker Joao Paulo and stout defenders Brad Smith and Yeimar Gomez Andrade.

2. Depth on Display

Pulido and Busio are on Gold Cup duty with Mexico and the United States, respectively, meaning that Sporting will have two notable holes to fill this weekend. Ilie, Roger Espinoza, Remi Walter and Cam Duke—who delivered an excellent performance in Wednesday’s 1-1 home draw against San Jose—are all capable of filling for Busio in the defensive midfield spot, while the likes of Khiry Shelton and Wilson Harris could spearhead the attack alongside wingers Salloi and captain Johnny Russell.

On the opposite sideline, Seattle posted an astounding 1-0 road win over Austin FC on Thursday night despite missing 10 players through injury and international duty. The Sounders’ lineup included a remarkable five teenagers—namely Ethan Dobbelaere, Reed Baker-Whiting, Danny Leyva, Josh Atencio and Obed Vargas—who performed admirably in the absence of six injured players as well as brothers Alex and Christian Roldan, who are on international duty at the Gold Cup. Schmetzer will almost certainly be forced to flex his team’s depth on Sunday.

3. Star Sounders

Ruidiaz (11 goals), Joao Paulo (five assists), Smith (three goals, three assists) and Gomez Andrade (the MLS leader in clearances and interceptions) have shouldered instrumental roles for the league’s best team. What makes Seattle’s start even more impressive is the fact that several standouts—namely forward Jordan Morris, midfield talisman Nicolas Lodeiro, goalkeeper Stefan Frei, striker Will Bruin and defender Nouhou Tolo—have missed significant time nursing injuries. No matter the circumstances, Seattle has kept rolling.


4. Seattle’s Fortress

Lumen Field has become a near-unconquerable fortress for the Sounders. This season alone, Seattle is unbeaten at home with a 5-0-3 record, five shutouts, 16 goals scored and four goals conceded. Since losing 2-1 to Portland on Sept. 6, 2020, the Sounders have gone unbeaten in 17 MLS home matches (including playoffs) with 13 wins and four draws. Perhaps more impressively, since taking a 3-2 home loss to Sporting on Aug. 4, 2019—the last time the teams faced each other—Schmetzer’s men have lost only once in 31 MLS home games (22-1-8 record).

5. History Lesson

Sporting and Seattle share a colorful head-to-head history, headlined by a dramatic 2012 Lamar Hunt U.S. Open Cup Final that saw Manager Peter Vermes’ side prevail on penalty kicks at Children’s Mercy Park. The Sounders lead the regular season series with a 9-7-4 record, including a 5-3-2 mark at Lumen Field, but Sporting have gone 6-2-3 in the last 11 meetings since 2015 after losing seven of the first nine from 2009-2014.

Sporting have won each of the last two meetings by a 3-2 scoreline, with Johnny Russell scoring a hat trick the last time Seattle visited Kansas City on May 26, 2019. The last four battles between the teams since 2018 have produced 18 total goals, a clip of 4.5 per match.