The American-born Arrieta sent 11 seasons in Italy, where he was raised, advancing as high as Serie B, where he played for Lecce, before heading to the USL-1 in 2008.
He has been a standout for the Islanders in his two seasons. He was an All-League selection and Defender of the Year in 2008 and made an even bigger splash this year as the runner-up in scoring with 25 points, tied with Charles Gbeke of Vancouver four back of Portland's Mandjou Keita. Arrieta tallied 10 goals, tied for fourth, and had five assists, tied for seventh. He helped lead Puerto Rico to a third-place finish at 15-7-8 while balancing another Concacaf Champions League competition.
Arrieta is the third player to earn Defender of the Year honors at least twice. Gabriel Gervais of the Montreal Impact won the award three times (2003-04, 06) and Scott Schweitzer of the Rochester Rhinos received the honor twice (1998-99).
Arrieta edged out Keita, the other finalist, for the Most Valuable Player honor. David Hayes of the Timbers and the Charleston Battery duo of Nelson Akwari and Matt Bobo were the other finalists for the defensive award.
Gavin Wilkinson of the Portland Timbers earned Coach of the Year honors. Wilkinson led the club from a worst-to-first turnaround, completely rebuilding the squad from a last-place finish a year ago and capturing the Commissioner's Cup as the regular-season champions with a 16-4-10 record. The Timbers had the best offense at 45 goals and tied for the best defense with Carolina at 19 allowed. They also shattered the league record with a 24-game unbeaten streak during the season.
Vancouver's Marcus Haber, 20, was named the Rookie of the Year. The Canadian youth international scored eight goals and recorded four assists for 20 points during the USL-1 regular-season campaign.
He is the first Whitecaps player to win the USL-1 Rookie of the Year award since Giuliano Oliviero won it back in 1995. In the postseason, Haber scored in both legs of the Whitecaps' semifinal upset of the Timbers.