Aaron Rowand was drafted by the Chicago White Sox in the supplemental first round of the 1998 draft, 35th overall, out of Cal State Fullerton. In college he drew praise as a power hitter with a strong throwing arm, but concerns about his strike zone judgment and ability to make firm contact kept him out of the first round. He went directly to Hickory in the South Atlantic League after signing, hitting .342/.410/.495 in 61 games, with a 21/36 BB/K in 222 at-bats. He would rate as something like a strong Grade B prospect.
Rowand spent all of 1999 with Winston-Salem in the Carolina League, hitting .279/.336/.504 with 24 homers, 15 steals, 33 walks, and 94 strikeouts in 512 at-bats. His production was safely above average in most respects, though the BB/K ratio reflected concerns about his eye. I gave him another Grade B in the 2000 book, writing that his performance in Double-A would tell us "if he will develop into a slugging star or merely a good hitter."
Moved up to Birmingham for 2000, Rowand hit .258/.321/.438 with 20 homers, 22 steals, 38 walks, and 117 strikeouts in 532 at-bats. He still showed power and a good glove, but the plate discipline issue was getting worse, and his overall production was only slightly better than league context. The MLE on his OBP was about .290. I gave him a Grade C+ in the '01 book, noting that I hadn't given up on the idea that he could improve.
Rowand split 2001 between Triple-A Charlotte (.295/.353/.526 in 82 games) and the White Sox (.293/.385/.431 in 63 games, 123 at-bats). His plate discipline looked better and he didn't have much trouble with major league pitching. Used as a platoon player in 2002, he hit just .258/.298/.394, then rebounded in '03 with a .287/.327/.452 mark. He finally took over a regular job in 2004 at age 26 with a .310/.361/.544, 130 OPS+, WAR 5.4 campaign.
Rowand has been up-and-down since then, with 2007 being his peak season (.309/.374/.515, 45 doubles, 27 homers, 124 OPS+, WAR 5.6 for the Phillies). He signed a five-year contract with the Giants at that point, with unimpressive results offensively; he's never gotten his OPS+ above 94 in San Francisco, and his defense is deteriorating as he ages.
Overall, Rowand is a career .275/.333/.440 hitter, OPS+ 100, WAR 23.9. Much of his value has been on defense: his OPS+ was better than league average just four times in 11 years, and two of those (2001 and 2003) were partial seasons with fewer than 400 plate appearances combined. His offensive career RAA is 24.3, but on defense he's 51.0. His overall performance is about what you'd expect based on his minor league numbers.
Most Similar Players through age 32: Mel Hall, Dan Ford, Wil Cordero, Bernard Gilkey, Troy O'Leary, Willard Marshall, Steve Kemp, Jacque Jones, Derek Bell, and Larry Hisle. Like Rowand, all of those guys were useful players with flaws, but who would post occasional All-Star quality performances.