Santos was drafted in the first round of the 2002 draft by the Arizona Diamondbacks as a shortstop out of Mater Dei High School in Santa Ana, California. He eventually worked his way up through the Diamondbacks' farm system upto Triple-A Tuscon. After reaching AAA ball in 2005 Santos stalled and was bounced around through trade and free agency before finally landing with the White Sox only to be shipped off again. However, only two weeks after being sent in a trade he was brought back to Chicago with the plan to be converted into a pitcher.
Throughout 2009 he pitched his way across the White Sox system and made the 2010 Opening Day roster as a reliever, winning the final bullpen spot in Spring Training. In 56 appearances he held batters to a .261 average and 2.96 ERA.
His 2011 campaign has built off his 2010 success and batters are only hitting at .161 clip with a 0.00 ERA in 15 games. Though not formally named the closer for the team manager Ozzie Guillen has used Santos effectively and he has collected 2 Wins and 5 Saves. If he continues to use his arsenal of off speed pitches with his 90's fastball Santos will continue to rack up the K's already having 22 against 9 Walks. So long as balls keep missing batters' bats Santos will prove to be an important part of the White Sox pen.