McCarthy went 3-for-4 with a double and a strikeout during Friday's 3-2 loss to St. Louis.
Feltner (4-6) picked up the loss after allowing three runs on four hits and three walks while striking out two over 5.1 innings in a 3-2 loss to the Cardinals on Friday.
Chapman (abdomen) will undergo season-ending surgery Tuesday, Alex Pavlovic of NBC Sports Bay Area reports.
Mayer (forearm) could be cleared to begin a rehab assignment next week, Alex Pavlovic of NBC Sports Bay Area reports.
The Giants selected Harris' contract from Triple-A Sacramento on Friday.
Brubaker will get the start in Friday's bullpen game against the Tigers, Susan Slusser of the San Francisco Chronicle reports.
Bericoto (oblique) went 1-for-3 with a double, an RBI and a run scored in Triple-A Sacramento's 13-10 extra-innings loss to Round Rock on Wednesday.
Leonard went 1-for-3 with a double in Wednesday's 6-0 loss to the Rangers.
Sugano (11-5) took the loss Wednesday against the Rays, allowing three runs on five hits and two walks over five innings. He struck out three.
Whisenhunt (2-3) took the loss Wednesday, giving up four runs on five hits and three walks over 3.1 innings as the Giants were downed 6-0 by the Rangers. He struck out four.
