Fresh off helping the Giants win the World Series for the first time since 1954, Sanchez is in good health to begin the season for the first time since being traded to the Giants from the Pittsburgh Pirates at the trade deadline in 2009 and has talked openly about being happy in San Francisco.
But the Giants are also reportedly high on the recent performance of their top second base prospect, Charlie Culberson, a possible factor, along with Sanchez's injury history, in influencing the length of the extension offer, as well as Sanchez' decision to retain more autonomy over his career after 2012.
Culbertson has never played above the Single-A level, but batted .290 with 16 home runs and 71 runs batted in with the San Jose Giants last season and followed that up with an impressive turn in the Arizona Fall League.
Sanchez, 33, batted .292 with seven home runs, 47 runs batted in and 55 runs scored in 2010, but has said he was never at full strength last year, even as he batted .270 with 21 total bases, four doubles, four RBIs, one walk and five runs in his first-ever postseason.
Left-shoulder injuries, which required two arthroscopic procedures in less than a year, as well as right shoulder and knee problems, have dogged Sanchez's tenure with the Giants and he missed the first 38 games of the 2010 season after being limited to 25 games over the final two-plus months of the 2009 campaign.
"I don't think it's a secret that I'm happy here," Sanchez told the Silicon Valley Mercury News during his negotiations with the Giants. "I feel part of the Giants family. This is a place I'd love to retire. But they've got to feel that way, too.
"I'm not going to worry about it. If I stay healthy and play the way I can play, things will take care of themselves."