Armstrong joined the Dallas Stars organization in 1991 and was appointed general manager on January 25, 2002. He won the Stanley Cup as an assistant general manager with the Stars in 1999. Armstrong replaced Bob Gainey as GM of the Stars with 32 games to go in the 2001–02 NHL season, and one of his first moves was hiring Dave Tippett as head coach. Armstrong is the son of NHL Hall of Fame linesman Neil Armstrong, inducted in 1991. On November 13, 2007, in the wake of a 7–7–3 start and a colossal meltdown by the team away against the Los Angeles Kings, Armstrong was fired as GM and replaced by former Stars player Brett Hull and assistant GM Les Jackson as interim co-general managers. During Armstrong's tenure, the Stars went 210–109–35–23 in the regular season, representing a.634 winning percentage, which is best in Stars history for a General Manager. Some important moves Armstrong made during his time as GM included the drafting of players like Trevor Daley, James Neal, Loui Eriksson and Jamie Benn. He also made a trade for Mike Ribeiro in exchange for defenceman Janne Niinimaa, which turned out to be beneficial for Dallas' offence.
St. Louis Blues
On May 29, 2008, the St. Louis Blues announced they had named Armstrong as the club’s director of player personnel after signing him to a two-year contract. When the two years were up, Armstrong became the club’s general manager after Larry Pleau’s retirement. On June 17, 2010, the Blues acquired goaltender Jaroslav Halak from the Montreal Canadiens in exchange for prospects Lars Eller and Ian Schultz. Although he had yet to officially take over duties as GM, this was considered to be Armstrong’s first big move as the GM of the Blues. In 2013, Armstrong was named the NHL General Manager of the Year and runner up again in 2019. In his ongoing tenure with the Blues, Armstrong has acquired many marquee players, including Martin Brodeur, Ryan O'Reilly, Vladimir Tarasenko, Jaden Schwartz, Alex Pietrangelo, Jay Bouwmeester, Paul Stastny and Ryan Miller. In 2018-19, Armstrong's Blues would surge up the standings for a third-place finish in the Central Division before eventually defeating the Boston Bruins in seven games to win their first Stanley Cup championship in franchise history. In Armstrong's ten seasons as General Manger with St. Louis, the Blues have won three Central Division Regular Season titles and reached the Stanley Cup Playoffs eight times, Divisional Finals four times, Conference Finals twice and won the Stanley Cup in 2019.
