San Francisco rewarded Sanchez with a new deal Friday that adds a $6 million salary for 2012, securing a key member of the infield for the World Series champions.
The contract was first reported by ESPN.com's Jerry Crasnick.
The 33-year-old Sanchez signed a $12 million, two-year contract extension with San Francisco on Oct. 30, 2009, after coming to the Giants at the trade deadline from the Pittsburgh Pirates that year.
Sanchez has dealt with his share of injuries in his short stint with the Giants. But the 2006 NL batting champion and three-time All-Star batted .254 with four doubles and three RBIs in 15 games in his first career postseason after nine years in the big leagues.
Sanchez was the first player in major league history with three doubles in his first three World Series at-bats.
Sanchez underwent arthroscopic surgery on his left shoulder in early December, his second such procedure on his non-throwing shoulder in a year. But that didn't slow him down much this spring.
The shoulder bothered Sanchez late in the regular season and during the improbable playoff run. Sanchez also had surgery on the same shoulder in December 2009 and began last season on the disabled list. This time, he received three opinions before going forward with the surgery, which athletic trainer Dave Groeschner said was essentially to cut the biceps tendon and clean up the back of his shoulder.
Sanchez batted .292 with seven home runs and 47 RBIs in 111 games last season as the Giants won their first NL West title since 2003 to end a six-year playoff drought. He then proved reliable at the plate and with his glove in the postseason.
Sanchez had left knee surgery after the 2009 season, when he was limited to 25 games for San Francisco because of injuries.
Information from The Associated Press was used in this report.