Armas was named the 16th Head Coach in club history on July 6, 2018. He subsequently led New York from third place to their third Supporters' Shield in six seasons with a 12-2-3 mark in the final 17 matches. The Red Bulls allowed just one goal in the final five matches, which helped surpass Atlanta on Decision day after Atlanta held the top spot for 23 of the prior 25 weeks. New York reached the Eastern Conference Finals for the first time since 2015 after advancing past Columbus Crew SC, 3-1, on aggregate.
In 2019, Armas led the Red Bulls to their 10th consecutive postseason appearances after a 14-14-6 mark in the regular season. New York tied the MLS record for most individual goal scorers with at least one goal in a season with 18, which was previously held by D.C. United in 2016. The Red Bulls also broke the MLS record for most individual assist makers with at least one assist in a season with 20.
He was an assistant coach for three and a half seasons, two of which as the top assistant, guiding New York's offensive attack. Under Armas' leadership, the Red Bulls attack tallied three-straight 50-plus goal and assist seasons, a Golden Boot Award winner (Wright-Phillips, 2016), and a back-to-back Silver Boot Award winner (Kljestan, 2016-17).
Armas was drafted by the Los Angeles Galaxy in the inaugural MLS draft in 1996 after two professional seasons with the Long Island Rough Riders of the USISL.
After two seasons with the Galaxy, Armas was traded to the Chicago Fire ahead of their inaugural 1998 campaign, the same offseason the club acquired Marsch. Armas played a large role in the Fire’s storied run to the 1998 MLS Cup and U.S. Open Cup double in their first season. Armas was named to the MLS Best XI for four straight seasons from 1998 through 2001 before seeing his streak broken by an ACL injury that caused him to miss much of the 2002 campaign. He bounced back in 2003, being named MLS Comeback Player of the Year and MLS Best XI for the fifth time. Armas is one of just four players to earn Best XI distinction five times, second only to Landon Donovan’s seven Best XI selections.
Armas played in 264 MLS regular season games, 260 of which were starts, recording 12 goals and 48 assists. Appearing in 37 playoff games, Armas found a bulk of his success with Marsch at the Fire, winning four Lamar Hunt U.S. Open Cup titles and an MLS Supporters Shield in addition to the 1998 MLS Cup. Captaining the side from 2003-2007, he was named an MLS All-Star six times and was voted team MVP in 2003.
He was also named U.S. Soccer’s Male Athlete of the Year in 2000. After the Fire’s double-winning campaign in 1998 Armas became a regular for the U.S. Men’s National Team, cracking the lineup just after the 1998 World Cup. He was part of the FIFA Gold Cup squads in 2002 and 2005, and was initially named to the 23-man roster for the 2002 World Cup in Japan before suffering an injury in a friendly leading up to the tournament. In all, Armas earned 66 caps for the United States.
Armas retired at the end of the 2007 season after 12 years in MLS. He served the following season as an assistant coach for the Fire under current Red Bulls sporting director Denis Hamlett. Armas returned to the New York area with his family, serving as head coach of the women’s varsity team at Adelphi University on Long Island from 2011 through 2014. Armas led the program to back-to-back conference title game appearances in the NE-10, and reached the ECAC Championship in 2014.