2010 Major League Soccer season

The 2010 Major League Soccer season was the 15th season of Major League Soccer. It was also the 98th season of FIFA-sanctioned soccer in the United States, and the 32nd with a national first-division league.

Negotiations between the league and the players' union resulted in a new collective bargaining agreement being agreed to on March 20, 2010. The new Designated Player Rule permitted teams to sign two such players, up from one under the previous rule, and pay a luxury tax of $250,000 for the right to sign a third.

The Philadelphia Union joined the league as its 16th team. The club's first two home games were played at Lincoln Financial Field while the construction of their permanent home, PPL Park in Chester, was being completed. The New York Red Bulls opened their new stadium, Red Bull Arena, on March 27 against the Chicago Fire.

The regular season began on March 25, and concluded on October 24. The LA Galaxy won the Supporters' Shield by one point over Real Salt Lake. The 2010 MLS Cup Playoffs began on October 28, and concluded with MLS Cup 2010 on November 21. The Colorado Rapids won their first MLS Cup by defeating the FC Dallas, 2-1, at BMO Field in Toronto. It was the first MLS Cup to be played outside the United States.

Season format
The season began on March 25 and concluded with MLS Cup on November 21. The 16 teams were split evenly into two conferences. For the first time in league history, the season had a balanced schedule where each team played every other team in the league once at home and once away for a total of 30 games.

The top two teams from each conference automatically qualified for the MLS Cup Playoffs. In addition, the four highest remaining point totals, regardless of conference, also qualified. In the first round, aggregate goals over two matches determined the winners. The conference finals were played as a single match, and the winners advanced to MLS Cup. In all rounds, draws were broken with two 15-minute periods of extra time, followed by penalty kicks if necessary. The away goals rule was not used in any round.

The team with the most points in the regular season was awarded the MLS Supporters' Shield and qualified for the CONCACAF Champions League. Additionally, the winner of MLS Cup, and the runner-up, also qualified for the CONCACAF Champions League. An additional berth in the Champions League was also awarded to the winner of the U.S. Open Cup. If a team qualified for multiple berths into the Champions League, then additional berths were awarded to the highest overall finishing MLS team(s) not already qualified. Also, Toronto FC, as a Canadian-based team, could not qualify for the CONCACAF Champions League through MLS, and had to instead qualify through the Canadian Championship.

Automatic qualification for the U.S. Open Cup was awarded to the top six overall finishers. The rest of the U.S.-based MLS teams had to qualify for the remaining two berths via a series of play-in games.

Personnel and sponsorships
Note: Flags indicate national team as has been defined under FIFA eligibility rules. Players and Managers may hold more than one non-FIFA nationality.

CONCACAF Champions League
The Columbus Crew continued their 2009–10 CONCACAF Champions League campaign that began during the previous season. They were defeated by Mexican club Toluca in the quarterfinals, 5–4 on aggregate.

Seattle Sounders FC became the first team to qualify for the 2010–11 CONCACAF Champions League by winning the 2009 Lamar Hunt U.S. Open Cup. The Columbus Crew qualified next by winning the 2009 MLS Supporters' Shield. The Los Angeles Galaxy and Real Salt Lake also qualified by being the two 2009 MLS Cup finalists, while Toronto FC took the Canadian berth by virtue of their Canadian Championship win. Los Angeles, Seattle, and Toronto entered the competition in the preliminary round, while RSL and Columbus were seeded directly into the group stage.

Seattle and Toronto won their preliminary round ties, beating Isidro Metapán of El Salvador and Motagua of Honduras, respectively. Los Angeles crashed out of the preliminary round after losing their home match 4–1 to the Puerto Rico Islanders of the USSF D-2 Pro League and failing to make up the deficit in the away leg.

The group stage was held August 17 – Oct 21. Real Salt Lake won Group A with 13 points over Cruz Azul, Toronto, and Arabe Unido of Panama. Toronto finished in 3rd place with 8 points. Columbus finished 2nd in Group B behind Club Santos Laguna but ahead of C.S.D. Municipal of Guatemala and Joe Public F.C. of Trinidad. Seattle finished 4th in Group C with 3 points behind C.F. Monterrey, C.D. Saprissa of Costa Rica, and C.D. Marathón of Honduras.

On November 1, the draw for the Championship round was held. Real Salt Lake will face Columbus in the quarterfinal in February/March 2011, immediately prior to the 2011 MLS Regular Season.

SuperLiga
As was the case for the 2009 SuperLiga, the top four overall finishers in MLS in 2009 that hadn't already qualified for the Champions League qualified for SuperLiga. This year's competition was contested by the Houston Dynamo, the Chicago Fire, Chivas USA, and the New England Revolution from MLS. The four Mexican teams were Pachuca, Morelia, Puebla, and UNAM.

New England, Houston, Morelia and Puebla advanced from their groups, with the Revolution beating Puebla on penalties in one semifinal, and Morelia defeating Houston in the other. Morelia defeated New England 2–1 in the final at Gillette Stadium on September 1.

Lamar Hunt U.S. Open Cup
The top six overall teams from the 2009 MLS season (Columbus, Los Angeles, Houston, Seattle, Chicago, and Chivas USA) received automatic berths into the third round of the 2010 U.S. Open Cup, while the eight remaining U.S.-based MLS teams and the expansion Philadelphia Union competed in a single-elimination qualification tournament to determine the MLS's final two official entrants into the competition. Teams were seeded one through nine, with the seventh-place MLS team from 2009 earning the first seed (and would play the winner of the eight v. nine play-in game), while each following team would receive its respective seed. The New York Red Bulls and D.C. United earned the final two MLS spots in the third round.

For the first time since 2006, the semifinals were contested exclusively by MLS teams, with Seattle beating Chivas USA and Columbus defeating D.C. United. The final was played October 5 at Qwest Field in Seattle with the defending cup holders, the Sounders, defeating the Crew 2–1. The Sounders became the first MLS team ever to successfully defend the U.S. Open Cup, and the first team from any league to do so since New York Pancyprian-Freedoms in 1983.

Canadian championship
Toronto FC, as a Canadian-based MLS team, is not eligible to compete in the Lamar Hunt U.S. Open Cup, and instead contested the Canadian Championship with the two Canadian-based teams in the Division-2 Pro League, Vancouver Whitecaps and Montreal Impact. Toronto FC won the tournament, claiming the Voyageurs Cup and Canada's entry into the preliminary round of the 2010–11 CONCACAF Champions League.