From BR Bullpen
Sergio Alberto Contreras Estrella
- Bats Left, Throws Left
- Height 5'11", Weight 180 lb.
- Born April 30, 1980 in Ciudad Obregon, Sonora Mexico
 Biographical information
 Anaheim system
On June 5, 1999, he was signed by the Anaheim Angels as a nondrafted free agent. His first professional year started out a little bumpy-in 63 games with the Angels of the Dominican Summer League, he hit only .252 with 2 home runs and 33 RBI.
His next season-2000 with the Butte Copper Kings-was a complete opposite of his first. In 45 games, he showed great contact by hitting .399/.467/.601. He managed to hit 3 home runs and drive in 28 runs as well. At one point in his 2000 season, Contreras had scored a run in 13 straight games. He easily outhit his twin brother, who also had a fine season for the team. Sergio did not qualify for the Pioneer League lead in average or he would have led the league.
With the Rancho Cucamonga Quakes, he hit .271 with 3 home runs and 37 RBI. His 15 stolen bases showed that he was developing more as a base-stealer than anything else.
In 2002, Contreras played with Rancho Cucamonga again, appearing in 81 games and hitting .271.
2003 was an off-year for Contreras. In 12 games with the Cedar Rapids Kernels, he hit only .176. When he played in Mexico that year, he was used as a bench player. He hit .272 for the Mexico City Red Devils, with 12 steals.
In 2005, he again spent his entire season in Mexico, hitting .314 with 9 home runs with 54 RBI.
His 2006 season also was in the Mexican League, this time with the Tigres de la Angelopolis. He hit .370 in 2006. In 2007, he batted .300/.388/.376 with 29 steals in 42 tries for the Tigres de Quintana Roo. He was third in the League in steals behind Demond Smith and Christian Quintero.
Contreras was with the Mexican national team in the 2007 Baseball World Cup and hit .419/.486/.710 with nine runs as one of the top performers on the 7th-place squad.
Sergio hit .305/.362/.397 with only 10 steals in 18 tries for Quintana Roo in 2008. In the 2008 Americas Baseball Cup, he did very well, going 9 for 18 with 2 homers and 7 RBI in 7 games. He tied for 5th in the event in both RBI and homers as Mexico earned a spot in the 2009 Baseball World Cup. In 2009, he hit .346 for the Tigers, while in 2010 he hit .323 and in 2011 he hit .347.