MLS is in the midst of their 24th season and the postseason is less than two months away. It's MLS Rivalry Week and there's certainly several big-time rivalries that have helped the tradition of the league over the years. For a look at everything you need to know about Rivalry Week, including the schedule and scores, click here.

With Rivalry Week in mind, it's worth taking a closer look at those rivalries and what has made them so important.  

1. Hell is Real (Columbus Crew/FC Cincinnati)

No matter the sport, in-state rivalries always get the juices flowing for residents of that particular state. That fact is definitely true for the "Hell is Real" rivalry between the Columbus Crew and FC Cincinnati. It's hard to get a more fearful nickname than "Hell is Real," especially considering that there's only 110 miles separating the two cities.

The rivalry gets its name from a sign that reads "Hell is Real" that a real estate developer put up on Interstate 71 just south of Columbus and it can be seen as you're heading toward FC Cincinnati. Cincy is currently in its inaugural season and has just five wins thus far. The two teams battled to a 2-2 draw in their first meeting this season back on Aug. 10 and now they'll face off once again on Sunday.

2. El Trafico (Los Angeles Galaxy/Los Angeles FC)

This is one of the shorter rivalries in the MLS since Los Angeles FC just began play in 2018. However, the name truly speaks for itself in a battle of two teams from Los Angeles. While the teams are just miles apart, it's a city that has more traffic than just about anywhere in the nation.

The two clubs met for the first time on March 31, 2018 and Los Angeles FC really took it to the Galaxy out of the gate as they had a 3-0 lead early in the second half. However, the Galaxy came away with a come-from-behind 4-3 win thanks to a pair of second half from Zlatan Ibrahimović. In the second installment later in 2018, Los Angeles FC Raced out to a 2-0 lead at halftime before seeing the Galaxy scored a pair of second half goals to secure the draw. The Galaxy also won a 3-2 decision in the first 2019 meeting earlier this season and will look for more success when the two teams face off on Sunday.

3. Canadian Classique (Montreal Impact/Toronto FC)

When you think of Canadian rivalries, most gravitate toward the Montreal Canadiens and Toronto Maple Leafs based on the fact that hockey is incredibly popular in Canada. However, the Montreal Impact and Toronto FC have really drawn the battle lines for their own rivalry in the MLS ranks. The name is great because it points out that these two teams are battling for respect of an another country. In addition, there's been a ton of success between the two franchises.

Despite the Impact being founded in 2010, the two teams have had several high-profile matchups over the years. In 2015, the Impact upended Toronto FC in the knockout round in a 3-0 rout. Two years later, Toronto FC was able to gain the upper hand in the rivalry with a victory over the Impact in the Eastern Conference finals and ultimately defeated the Seattle Sounders to win the MLS Cup.

4. Atlantic Cup (D.C. United/New York Red Bulls)

It's hard to think about the MLS without considering what D.C. United and the New York Red Bulls have meant to the sport. There's so much tradition of excellence in sports in the Mid-Atlantic region of the United States and the Atlantic Cup is no different.

It's the longest rivalry in the MLS as it has spanned 23 years and continues to produce drama in a battle between two of the biggest sports markets in the United States. There have been 94 meetings over the years and D.C. United has recorded 43 wins to gain the edge in the series. Most recently, the Red Bulls came away with a 2-1 win on Wednesday in a very crucial game with just two wins currently separating the Red Bulls and D.C. United in the standings. Considering the amount of star power that has been involved in this rivalry, even with Wayne Rooney going back to England, the rivalry shouldn't lose any of its luster.

5. Cascadia Cup (Seattle Sounders/Portland Timbers/Vancouver Whitecaps)

When it comes to a rivalry, there can be a lot of hatred involved and that couldn't be more true in the Pacific Northwest when it comes to the Seattle Sounders and Portland Timbers. The Cascadia points to the region in the Pacific Northwest where both of these teams hail from and that alone makes it worthy of the list.

The Cascadia Cup trophy was created in 2004 by supporters of the Sounders, Timbers, and Vancouver Whitecaps. It has gone back-and-forth in recent years with the Sounders most recently winning it in 2018. The Sounders and Timbers have won two of the last four MLS Cups and have met in the playoffs on countless occasions. With the two teams being in the same geographical region, this rivalry has had a ton of bad blood over the years in several high-profile matches.

Honorable Mention

Rocky Mountain Cup: The Rocky Mountain Cup is another sensational rivalry that pits the Colorado Rapids and Real Salt Lake against one another. Real Salt Lake has won 20 of the 47 matches since the series began in 2005.

Hudson River Derby: The Hudson River Derby is another new rivalry between the New York Red Bulls and New York City FC. While New York City FC has only been in existence since the 2015 season, it's always appealing when professional teams from the New York area do battle. Considering they're so close to one another, it could blossom into a sensational rivalry for the fanbases of both clubs.

California Clasico: This is another rivalry that pits in-state rivals against each other in the San Jose Earthquakes and Los Angeles Galaxy. With just a few hours separating the teams, it's no surprise that this rivalry deserves to be mentioned. On top of that, the teams have combined to win seven MLS Cups over the years.