Josh Rutledge will be the latest to get a chance to start at third base for manager John Farrell.
"There's been a number of changes there," said Farrell. "The injuries. The number of errors made down there. I've considered an exorcism at third base, see if we can clean things up in some form or fashion. But right now it's going to be Rut."
Sandoval has been on the disabled list since April 25 with a right knee sprain and is still waiting to be cleared to return to baseball activities.
Holt was placed on the DL on April 21 with vertigo, and was scratched from a Minor League rehab assignment earlier this week due to recurring symptoms. The Red Sox hope he can resume action in the Minors on Saturday.
At this point, president of baseball operations Dave Dombrowski doesn't envision adding a third baseman from outside the organization. Promoting Red Sox No. 1 prospect Rafael Devers isn't on the radar either.
"Not at this point," said Dombrowski. "We'll wait and see with Pablo, when he'll be coming back. We'll get Brock back here. Devers has done great. He's in Double-A at 20 years old right now. We're happy where he is right now. We like him a lot. He's having a great season. And we're not ready to jump outside the organization."
Hernandez hurt himself while making an error in the first inning on Wednesday.
Kyle Kendrick, who started Thursday against the Orioles, was promoted from Triple-A Pawtucket in a corresponding move, and the club transferred reliever Tyler Thornburg to the 60-day DL.
Hernandez, who is typically a reserve utility infielder, had started the past eight games for Boston -- seven of them at third base.
Hernandez is hitting .276/.300/.328 in 21 games this season after posting a .294/.357/.373 line as a rookie in 2016.
Ian Browne has covered the Red Sox for MLB.com since 2002. Follow him on Twitter @IanMBrowne and Facebook. This story was not subject to the approval of Major League Baseball or its clubs.