Before Friday's game, Giants manager Bruce Bochy laid out a four-game schedule Roberts is expected to follow before his potential return to the active roster on Wednesday.
Roberts, a 10-year veteran outfielder, has been on the disabled list since early April following surgery on his injured left knee. He began a rehab assignment with Triple-A Fresno on July 7 and, before Friday night, was 5-for-16 in six games.
He'll play seven innings with the Grizzlies on Friday night and play nine innings on Saturday and Sunday. On Monday, he'll play an undetermined amount before resting Tuesday and likely be activated Wednesday.
In his place, 27-year-old Fred Lewis has played 92 games and batted .275 with a .448 slugging percentage. Bochy previously insisted that Roberts' return wouldn't force Lewis into a bench role. It should be noted, though, that Lewis hit a mini-slump heading into the Midsummer Classic, batting .241 in the 15 games preceding the break.
It's likely Roberts will serve as an experienced left-handed hitter off the bench, something the Giants have been without most of the season.
David Biderman is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.