He played in Nippon Professional Baseball (NPB) for the Orix Buffaloes and in the KBO League for the Hanwha Eagles.

From that point on, he did not give up more than two runs in an appearance for the rest of the season, and converted his first seven save opportunities to earn himself a Midwest League All-Star nod.

Thus, he began the 2008 season in the starting rotation of the Florida State League Class A advanced Daytona Cubs.

[2] The Cubs released Maestri in April 2011,[3] and he signed with the Lincoln Saltdogs of the American Association of Independent Professional Baseball.

Starting against the Canberra Cavalry, Maestri went five innings and gave up two hits, picking up the first win of the Bandits' 2011-12 season.

The Bandits ended the half a game short of the playoffs, with Maestri posting a 3.25 ERA and a 1.16 WHIP en route to winning the ABL's Fan Choice Award.

Maestri played portions of 2012 for the Rimini Baseball Club and the Kagawa Olive Guyners of Japan's Shikoku Island League.

[10] On April 10, 2017, Maestri signed with the Rojos del Águila de Veracruz of the Mexican Baseball League.