Knizner signed a major-league contract with the Giants on Tuesday, Justice delos Santos of The San Jose Mercury News reports.
Knizner has yet to play in an MLB game this season, but he's slashed .294/.393/.552 with 12 homers, 38 RBI and 33 runs scored across 234 plate appearances at Triple-A. He'll now reunite with the Giants to provide depth at catcher, replacing Zach Morgan.