"I haven't had a chance to talk to Angel yet, but we may have to make a move," said Bochy after the game. "Hopefully we'll get good news tomorrow."
Pagan had been 0-for-3 with a walk against San Diego left-hander Drew Pomeranz before departing the game.
Luckily for the Giants, outfielder Hunter Pence, who hit Monday's walk-off double, is almost fully recovered from a hamstring injury of his own, which will help prevent the outfield situation from becoming too thin if Pagan's injury necessitates a trip to the disabled list.
If Pagan were to hit the disabled list as a result of the injury, the Giants would likely call up either Jarrett Parker or Mac Williamson from Triple-A Sacramento in a corresponding roster move.
Both players saw brief stints with the Giants during Pagan's absence earlier this month, with Parker collecting one hit in four at-bats and Williamson going 3-for-13 with an RBI.
Kelby Tomlinson also made a start in left field on Saturday and could reprise that role if needed. Tomlinson is hitting a team-leading .455 in the month of May to boost his average to a team-best .339, and Bochy has voiced his desire to keep the infielder's hot bat in the lineup.
Do-Hyoung Park is a reporter for MLB.com based in San Francisco. This story was not subject to the approval of Major League Baseball or its clubs.