The ballot launched Wednesday, and Castillo is on it, representing the Mets at second base.
"If I were to make the team, I'd feel really good about that," Castillo said. "My last All-Star Game was in 2006, and that's my goal, to make the All-Star team with the Mets. But it's early, and we have a lot of games left before that."
Fans can cast their votes for starters up to 25 times with the 2009 All-Star Game Sprint Online Ballot at MLB.com and all 30 club sites until July 2 at 11:59 p.m. ET.
Starting rosters will be announced during the 2009 All-Star Game Selection Show presented by Chevrolet on TBS on July 5. Baseball fans around the world will then be able to select the final player on each team via the 2009 All-Star Game Sprint Final Vote at MLB.com.
And the voting doesn't end there. Fans will have the opportunity to participate in the official voting for the Ted Williams Most Valuable Player Award presented by Chevrolet at the Midsummer Classic via the 2009 All-Star Game Sprint MVP Vote at MLB.com.
The All-Star Game will be televised nationally by FOX and around the world by Major League Baseball International. ESPN Radio will provide exclusive national radio play-by-play, while MLB.com will offer extensive online coverage.
For Castillo, the ballot is a chance to return to a place many thought he might never reach again: the All-Star stage. An NL All-Star reserve in 2002, 2003 and 2004, Castillo never made the cut in his two seasons with the Twins, and didn't come particularly close in his first year with the Mets. But healthier and lighter than he has been in years, Castillo has led New York in hitting for most of the first month of the season.
"I feel healthy," Castillo said. "Last year I had surgery, so I came in a little bit overweight and wasn't healthy, but I worked in the Dominican all winter and I lost 17 pounds and my body feels good. The whole winter I was losing weight and working out and hitting and everything. I came ready this year.
"This game is not easy, and I'm just trying to do my job and help us win some games."
Castillo faces stiff competition on the ballot from a strong class of NL second basemen -- Chase Utley, Dan Uggla and Orlando Hudson among them -- but has also, at least so far, put up numbers with the best of them.
Compared to some of his teammates, however, Castillo seems somewhat less likely to receive an All-Star nod. Jose Reyes, who missed last year's game due to a disappointing first month of the season, is again among the favorites at the shortstop position. David Wright, one of the game's most talented and popular sluggers, is on course to make the squad as a third baseman for the fourth consecutive year.
Carlos Beltran, who, like Reyes, turned in a disappointing April last season and missed the All-Star Game, is in the running to make his fifth roster in the past six years. And as long as Carlos Delgado continues hitting as he did in the second half of last season, he could be in line for his third career All-Star Game, and his first since 2003.
The other Mets on the ballot are Ryan Church and Daniel Murphy in the outfield and Brian Schneider at catcher. Murphy is on the ballot for the first time in his career.