[7] Before beginning his coaching career, Arena was a goalkeeper for Cornell University, and earned one cap with the United States men's national soccer team.
While in high school, he also played a single season with local club Hota S.C. of New York City's Cosmopolitan Soccer League.
That year, in addition to playing for the Tides, Arena coached the men's soccer team at the University of Puget Sound, where he compiled a 5–7 record.
Arena was the head coach of the Virginia program for eighteen years, during which he won five national championships (including 4 straight from 1991 to 1994) and amassed a 295–58–32 record, for a career NCAA mark of 300–65–32.
Additionally, he coached and developed many players at Virginia who would go on to play significant roles in the United States national team, including Claudio Reyna, Jeff Agoos, Ben Olsen, John Harkes and Tony Meola.
Despite the underperformance at the Olympics, Arena managed to form his team and lead United to an improbable comeback victory in the first MLS Cup at Foxboro Stadium.
The heavily favored team won its second MLS Cup at RFK Stadium defeating the surprise Western Conference champion Colorado Rapids 2–1.
In 1998, Arena took United to its third consecutive MLS Cup only to see his team fall to the expansion Chicago Fire led by his protégé Bob Bradley.
However, while Arena failed to add another MLS championship to his resume, he guided United to the CONCACAF Champions' Cup title with a 1–0 victory over Toluca on August 16, 1998.
A hard-fought tie against host nation South Korea was enough to qualify for the second round, despite a poor loss against Poland in the final group game.
The U.S. switched from their usual 4–4–2 to a 3–5–2, and it paid dividends almost immediately when Josh Wolff, who Arena had brought in to fill out the formation, set up Brian McBride for the winning goal early in the first half.
[23] The U.S. national squad fell short of expectations at the 2006 FIFA World Cup, finishing last in Group E with losses to the Czech Republic and Ghana.
Some, including former team member and ESPN analyst Eric Wynalda, have blamed the poor performance on questionable coaching decisions by Arena, including not playing Clint Dempsey and putting DaMarcus Beasley on the right wing instead of his favored left against the Czechs, and using a defensive 4–5–1 in the must-win match vs. Ghana which the U.S. eventually lost.
[citation needed] During his time as national team head coach, the United States rose in the FIFA world rankings from nineteenth to fourth, to the surprise, even, of U.S.
Nevertheless, three weeks after the Americans' disappointing first-round exit from the World Cup in Germany, the U.S. Soccer Federation announced that Arena's contract would not be renewed when it expired at the end of 2006.
"[25] Arena was eventually replaced as national team coach by his close friend and former assistant at Virginia and D.C. United, Bob Bradley.
On August 18, 2008, Los Angeles Galaxy hired Arena to replace Ruud Gullit as head coach and Alexi Lalas as general manager.
During the offseason, Arena reshaped the defense, drafting Omar Gonzalez and A. J. DeLaGarza who became fixtures on the backline and bringing in Donovan Ricketts as the goalkeeper.
On November 22, 2016, Arena was appointed as coach of the United States national team for the second time, replacing Jürgen Klinsmann after two disastrous losses in the first two matches of Hex qualifying round for the 2018 World Cup.
On October 10, the final day of qualification, the USMNT needed a draw against Trinidad and Tobago to qualify for the 2018 FIFA World Cup in Russia.
The U.S. were heavy favorites[32] coming in as Trinidad and Tobago had lost six straight games, but the team fell into a 0–2 hole with an Omar Gonzalez own-goal and an Alvin Jones goal.
[38] Under Arena, the Revolution, who were at that point in last place in the Eastern Conference, went eleven games undefeated until losing 2–0 to Los Angeles FC on August 3, 2019.
[46] Despite the strong regular season, the Revolution were eliminated in penalties in the 2021 MLS Cup Playoffs Conference semifinals by eventual champion New York City FC.
[47] After a transfer and injury-hampered 2022 campaign,[48] Arena's Revolution returned to form in 2023, compiling a record of 12 wins, 7 draws, and 4 losses, sitting in second place in the Eastern Conference, when regular season play paused for the 2023 Leagues Cup.
[54] He has a brother, Michael, and a son, Kenny Arena, who played with the U.S. youth national team and in Major League Soccer before becoming a coach.