Dominguez was drafted by the Marlins in the first round in 2007, 12th overall, signed out of high school in Chatsworth, California. He was considered a solid power hitter with an excellent glove at third base. He hit .296/.354/.499 with 18 homers for Greensboro in the Low-A South Atlantic League in 2008, but has been less effective with the bat in subsequent seasons. He hit .247/.325/.400 with 13 homers combined between High-A and Double-A in 2009, then .252/.333/.411 with 14 homers in Double-A in 2010. Moved up to Triple-A this year, he hit .258/.312/.431 with 12 homers, 24 walks, and 50 strikeouts in 325 at-bats for New Orleans.
All told, he is a career .255/.325/.418 hitter with 166 walks and 325 strikeouts in 1956 minor league plate appearances. This is hardly the minor league performance you would expect from a future star, although a saving grace is that he has been young for his leagues.
Dominguez looks the part of a power hitter physically. He makes an effort to control the strike zone and isn't excessively prone to whiffing, but he can be busted inside with fastballs, or made to chase stuff outside the zone for weak contact. His bat speed is far from explosive, although he's worked to smooth out his stroke. The hope is that with additional experience will make him a decent hitter, someone who can hit .250-.270 with 15-20 homers per year. Given his youth (he just turned 22), this isn't too much to ask or expect.
If Dominguez can be even adequate with the bat, he'll have a long career: his glove is excellent. He has a strong and accurate throwing arm, soft hands, and (although his outward athleticism isn't exceptional) superior range. He anticipates with the best, and seems to come out of nowhere to make plays other third basemen don't reach. Unlike many young infielders with flashy defensive skills, Dominguez is also reliable on routine plays and commits few mental mistakes. He is capable of winning Gold Gloves once he settles in.