Duffy hit solo home runs in the second, fourth and eighth innings for the third multi-home run game of his career. He also homered Sunday in Omaha and now has four homers in the past two games.
The RedHawks infielder became the second player in the PCL to hit three homers in a game this season, following Tacoma's Jabari Blash, who did it June 3 against El Paso.
Duffy had struggled early on with OKC since being promoted to the Astros' top affiliate. He was just 2-for-23 prior to Sunday's action. Since then he has hit four homers and raised his average to .194 with the four home runs and seven RBIs. Duffy hit .302 with Corpus Christi before being recalled in late May.
Simunic, 28, was the 17th round selection of the Houston Astros in the 2008 June draft out of the University of Tennessee. He batted .276 with 59 doubles, eight triples, 11 home runs, 161 RBIs and 64 stolen bases over parts of seven seasons in the Astros' organization. Simunic played 30 games with Triple-A Oklahoma City this season, batting .263 (25-for-95) with five doubles, one home run, 10 RBIs and one stolen base. He was released by the Astros on June 1.