Theriot's veteran presence complements that of young shortstop Brandon Crawford and also offers insurance if the rehabbing Freddy Sanchez (right shoulder) is not deemed ready to play second base by the start of the season.
San Francisco has yet to officially announce the non-guaranteed deal, which is said to be pending a physical. Theriot would reportedly make $1.25 million if he makes the team and could potentially bring in another $750,000 in incentives.
Theriot, non-tendered by the Cardinals in December, played shortstop and second base for St. Louis during its World Series championship season, batting .271 with one home run and 47 RBIs in 132 games.
The 32-year-old also made 12 playoff appearances, including five in the World Series. He's embarking on his eighth Major League season, having compiled a .282 career batting average and a .344 on-base percentage in a combined 795 games.
Theriot's .301 career mark against lefties is very much welcomed, given Crawford's left-handed bat, and could set him up to platoon with the youngster.
There should be plenty of competition, though, with Mike Fontenot and Emmanuel Burris still aboard as infield options. The lefty-hitting Fontenot, who played with Theriot for several years with the Cubs, has a guaranteed contract, while Burris is out of options.