Grabavoy played his youth soccer with the Chicago Magic Soccer Club under coach Mike Matkovich from U12 through U19. Grabavoy’s U16 Chicago Magic team was credited with winning the Chicago Magic Soccer Clubs first National Youth Soccer Club Association Championship in 1999. Grabavoy attended Lincoln-Way High School. Grabavoy led the Knights to two straight Illinois State Class AA Championship games, and as a senior, was named the 2000-01 Gatorade National High School Player of the Year. Grabavoy played three years of college soccer for the Indiana University Hoosiers under legendary coach Jerry Yeagley. Grabavoy was a unanimous All Big-10 selection as a sophomore, and was voted an NCAA First Team All-American as a junior. Grabavoy led Indiana University to a 2003 Men’s NCAA Championship his third year.

Grabavoy played for coach Mike Matkovich with the Chicago Fire Reserves in the Premier Development League, and signed a Project-40 contract with MLS, and was subsequently selected 14th overall in the 2004 MLS SuperDraft by the Los Angeles Galaxy and Coach Sigi Schmid. In his first year with the Galaxy, Grabavoy played 928 minutes, registering a goal and three assists. He added three assists in his second season, while fighting for playing time as LA won the MLS Cup and U.S. Open Cup double. In May 2006, Grabavoy was traded to the Crew in a four-player deal.

Grabavoy was selected by the San Jose Earthquakes in the 2007 MLS Expansion Draft. He was waived by the club on March 3, 2009, but was picked up by Real Salt Lake in the Waiver Draft later that same day. Grabavoy scored the winning penalty kick on November 14, 2009 at Chicago Fire to give Real Salt Lake their first conference championship and first trip to the MLS Cup final. Real Salt Lake beat Los Angeles Galaxy in the final for its first championship. He scored his first Real Salt Lake goal on May 29, 2010 against the Kansas City Wizards at Rio Tinto Stadium, the fourth goal in a 4-1 RSL victory.

In January 2012, RSL signed Grabavoy to a contract extension through the 2013 season. The following month the contract was extended an additional year through 2014.

On December 10, 2014, Grabavoy was selected second overall by New York City FC in the 2014 MLS Expansion Draft. In 2015, Grabavoy played for New York City FC rejoining Coach Jason Kreis whom he had played for at Real Salt Lake from 2009 though 2013.

In 2016, Grabavoy was part of the first Major League Soccer “free agent class.” Grabavoy signed with Portland Timbers on January 12, 2016.

On October 18, 2016, Grabavoy announced his retirement effective at the end of the 2016 season. He was named as director of scouting and recruitment for the Portland Timbers (Major League Soccer) in December 2016.