Duvall provides a reinforcement at first, after starter Brandon Belt went on the seven-day concussion disabled list Friday. Duvall was penciled into the fifth spot in the lineup and started at first for the Giants on Sunday.
"We've got some left-handed pitching coming up here, and [Duvall can] help out at first with [Travis] Ishikawa," Giants manager Bruce Bochy said.
In a corresponding roster move, San Francisco optioned outfielder Juan Perez to Fresno.
Perez compiled a .175/.246/.286 slash line in 71 plate appearances.
Jackson Alexander is an associate reporter for MLB.com.