"I don't love the idea of using guys twice," Hinch said. "That's not to say that I won't. A lot will depend on what we need. You try to win the first game, and whatever it takes to win the first game is what I'll go with, both in who and in volume.
"We'll make the decision later in the day what happens after that. We'll have an extra pitcher for the second game -- Diaz is here -- to be our 26th man once the second game starts. We'll have some reinforcements."
Diaz, whose previous Major League experience covered six appearances last season for the Reds, appeared in 10 games at Triple-A Fresno and allowed 10 hits, three runs, five walks and 15 strikeouts in 13 2/3 innings for a 1.10 WHIP.
Diaz, a Colombian who pitched in the World Baseball Classic this year, was originally signed by the Astros in 2005 and spent seven years in the organization before being re-signed in February.
Meanwhile, Houston starting pitchers Joe Musgrove (Monday) and Dallas Keuchel (Tuesday) were scheduled to fly to Miami on Sunday night so they could avoid a late-night flight. The Astros aren't scheduled to land in Miami until 4:30 a.m. ET on Monday.
Brian McTaggart has covered the Astros since 2004, and for MLB.com since 2009. Follow @brianmctaggart on Twitter and listen to his podcast. This story was not subject to the approval of Major League Baseball or its clubs.