Sanchez started his career by signing a free agent contract with the Boston Red Sox in 2001. After playing exclusively in the Minor Leagues for his first five professional seasons, he was traded from Boston along with Hanley Ramirez, Jesus Delgado and Harvey Garcia to Florida for Josh Beckett, Guillermo Mota and Mike Lowell.

To date, Sanchez has spent his entire six season Major League career with Florida. In his 2006 Major League debut, he posted a 10-3 record with a 2.83 ERA and a 1.190 WHIP, finishing ninth in the year-end voting for NL Rookie of the Year.

Sanchez was plagued by injuries for the next three seasons. Between 2007 and 2009, Sanchez started a total of 32 games, collecting eight wins against 14 losses and a 4.56 ERA. His WHIP was an albatross-like 1.628.

2010 would finally see Sanchez put together a complete season for the Marlins. He collected 13 wins for Florida against only 12 losses and a 3.55 ERA over his 32 starts. He also struck out over two batters for each walk.

Sanchez continued to mature in 2011. He struck out a career high 202 batters, good for sixth best in the NL and just over one per inning pitched. He finished the season 8-9 with a better than average 3.67 ERA.

Sanchez projects as the Marlins number three starter for the 2012 season, behind Josh Johnson and Mark Beurhle.