Vitters is something of an AFL veteran, having played in the league for the past three years.
"I was excited," he said about returning to Arizona. "I've been really excited to be here the last few years. It's great to play at this level. You know you're going to face good pitching every day."
Vitters will be working on defense at several different slots during the fall.
"I'm going to be playing a lot of different positions -- corner infield and corner outfield," he said. "It'll be good for me to get that experience. It'll definitely help me become more versatile on defense."
Indians prospect Jesus Aguilar gave Phoenix a 2-0 lead in the first inning with a two-run homer off Cole DeVries (Braves).
Vitters' three-run homer capped a five-run third for Mesa. Robbie Grossman (Pirates) also hit a two-run shot off Phoenix starter Murphy Smith (A's).
The Desert Dogs added another run in the third on a fielder's choice before collecting six more in the fourth when Anthony Gose (Blue Jays) ripped a two-run bases-loaded double, Corban Joseph hit a three-run homer and fellow Yankees prospect Ronnier Mustelier added a two-out RBI triple.
Phoenix wasn't done, though -- Gose led off the sixth with a homer to center off Phil Irwin (Pirates), and two batters later, A's slugger Michael Choice tacked on a solo shot to left. The Dogs added a run in the eighth when Joseph scored on an error by Twins shortstop Brian Dozier.
Smith lasted 2 2/3 innings in the start, allowing three runs on three hits on a walk. He struck out two.
DeVries was charged with three runs on five hits over 2 2/3 innings for Mesa.
"It's definitely more about working on your own game than the regular season is," Vitters said. "But you you still want to win and we definitely want to win the whole thing."
Vitters is already familiar with most of his teammates, some of whom he's played against and others whose names he has heard before.
"We've playing pretty well together so far in the practices and in the first game," he said. "Hopefully we'll do a little better. We did get the loss."