GL Rough Diamonds

Greater Lowell United FC was founded in 2013 as an expansion team to join the National Premier Soccer League (NPSL) for the 2014 season. GLUFC also fielded two junior teams that season, one in the Massachusetts State Soccer League (MSSL) and one in the Bay State Soccer League (BSSL). The club dropped the MSSL team after the 2014 season but kept a team in the BSSL. In 2015, GLUFC's junior team was only competing in the second half of the 2015 BSSL season.

GLUFC's top team played three seasons in the NPSL, a national amateur league that includes reserve teams from North American Soccer League (NASL) clubs. In 2014, the team won one game, drew one game and lost 10 games. GLUFC struggled early on under Coach Jason Moore, a former Major League Soccer (MLS) No. 1 draft pick, but rebounded under Coach Daniel Hristov, who replaced Moore after the second game of the season. Shortly after Hristov's arrival, the 2014 team beat the Rhode Island Reds, 2–0, in Bedford, and drew 0–0 with New York Athletic Club in Lawrence. However, Hristov and the club parted ways for the 2015 NPSL season, which saw Luis Costa arrive as head coach. Costa's sides performed well in several matches but failed to achieve results, losing 9 games and drawing one before Costa departed the club with two games left to play. Hayden Barbosa, an assistant coach at Daniel Webster College, coached the final two games, both of which were losses, including a 2–1 decision dropped to eventual undefeated NPSL champions New York Cosmos B in New York.

Barbosa took over as coach of the NPSL team for the 2016 season.

In 2015, goalkeeper Sam Manning earned a spot on the soccer team at Millersville University.

In 2016, GLUFC left the NPSL, parting with its former co-owner and manager Andrea Gauntlett, who retained the right to field an NPSL team in the Greater Lowell area. GLUFC joined the CSL USA for the 2017 season. The club was placed in the league's North-East Division.