His major achievements included winning the USL Championship, Commissioner's Cup, and receiving All-League honors on four separate occasions in his career.

Portland club won the USYSA U-18 national championship with Gregor taking MVP honors.

Portland, Gregor played for Sunset High School boys team, being a two-time, all-state selection.

On November 14, 2002, the Cleveland Crunch signed Gregor to a two-year contract.,[4] but he played only thirteen games and was released at the end of the season.

Gregor returned to the Sounders for the 2003 season, where he posted a career high seven assists, along with seven goals, once again earning first team All Star recognition.

In Portland he managed to claim the club's first piece of silverware by leading the Timbers to a regular season championship.

In 2007, he played twenty-four games with the Timbers, earning first team All Star recognition for the fourth time in his career.

In the club's playoff run the Rhinos defeated the Charleston Battery in the quarterfinals to advance to the semifinals.

The following season Gregor led the Rhinos to a sixth-place finish in the standings enough to clinch a playoff spot.

[7] In May 2023, Gregor was named director of scouting for Major League Soccer club Minnesota United.