"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.

The inaugural meeting between MLS original Sporting Kansas City (1-1-1, 4 points) and expansion side Austin FC (2-1-0, 6 points) will take place Sunday under the lights at world-class Children's Mercy Park.

The high-profile Western Conference clash is slated for 6:30 p.m. CT and a very limited number of tickets are available at SeatGeek.com while supplies last. Supporters can catch Sunday's showdown nationally on FS1, FOX Deportes and the FOX Sports app, while Sports Radio 810 WHB and La Grande 1340 AM will air local radio broadcasts.

Without further ado, we dive into five compelling storylines surrounding the contest in the space below.

1. Sporting Reunion

A Sporting reunion several months in the making will come to fruition on Sunday when three club legends return to Kansas City as members of the opposition. Austin FC head coach Josh Wolff, assistant Davy Arnaud and defender Matt Besler, three of the most accomplished MLS players in Kansas City history, will go head-to-head against Manager Peter Vermes and Sporting in the final fixture of Week 4.

All three individuals have left indelible marks on the field while donning a Kansas City uniform, combining for 784 competitive appearances and seven MLS All-Star selections as members of the club. Five of Sporting's seven major trophies were secured with Wolff, Arnaud or Besler as an integral member of the squad.

2. Pulido on Point

In an otherwise forgetful 3-1 road loss to rivals Real Salt Lake last weekend, Sporting striker Alan Pulido offered a prompt reminder of his undeniable quality by notching his team’s lone goal in impressive fashion.

Sporting's club-record signing had been limited to second-half substitute appearances in the first two matches of the 2021 MLS campaign due to an injury sustained in preseason. Making his first start against RSL, Pulido picked up where he left off last year as one of the most prolific players in the league.

In fact, since the start of 2020, the Mexican international ranks second in MLS with 0.973 combined goals and primary assists per game in the regular season. He has scored or assisted in nine of his 12 career regular season starts.

3. Awesome Austin

Austin FC have won two of their first three matches as an MLS debutant and will open the season with eight straight road games. Designated Player Cecilio Dominguez and midfield playmaker Diego Fagundez have bagged two goals apiece, while Besler anchored a stout defensive effort that saw Austin post a 1-0 shutout win over Minnesota United FC on Saturday. New expansion teams have a reputation for struggling in year one. If the first three weeks of the 2021 campaign are any indication, Austin is perfectly capable of bucking that trend.

4. Milestones Approaching

Just as Besler makes his return home, it seems poetically fitting that one of his closest friends could make history of his own. Graham Zusi, who has been sidelined since last October with a foot injury, is one shy of his 295th regular season appearance for Sporting. That would vault Zusi ahead of Besler and into sole possession of first place in team history. Additionally, captain Johnny Russell is one shy of his 100th competitive appearance for the club.

5. Youth Movement

Sporting is quickly becoming one of the youngest, most Academy-based teams in MLS. The club signed 18-year-old outside back Kayden Pierre (above) on Tuesday and now has 12 academy products on its roster, the most in Major League Soccer. The average age of the 29-man roster, despite having seven players north of 30, is just 25 years old.