The Quakes are the only team in the Western Conference without a point through two games, though a big-name reinforcement could be coming soon.
The West Coast Conference tournament looms next weekend in Las Vegas before Selection Sunday.
Chapman, a four-time Gold Glove third baseman, turned down a qualifying offer from Toronto to join the Giants, meaning San Francisco must forfeit a second-round draft pick and international signing bonus pool money to acquire him.
Mason Black, Spencer Howard, Sean Hjelle represent top internal options but Blake Snell, Jordan Montgomery remain available.
Preston Judd's goal in the 70th minute helps Quakes avoid shutout and worst home-opening loss since joining MLS in 1996
Results from Saturday's California Interscholastic Federation NorCal boys, girls basketball semifinals, championship game matchups.
The Gaels will be the WCC's top seed in the conference tournament, but their win streak ends at 16 games.
