"Having his name in that lineup is very reassuring," Francona said of Ramirez. "But I think it's a good night, the way [Chamberlain's] throwing the ball, the way Manny's been swinging at certain types of pitches."
While Chamberlain has added a variety of pitches to his repertoire for the transition to the starting rotation, he is still known for his high-velocity fastball, and Francona said the fastball has been beating Ramirez lately.
The Red Sox's slugger has run into a recent slump at the plate. He has gone 5-for-30 on the team's road trip, and is hitting .185 in his past 20 contests.
A sore right hamstring has pestered Ramirez for nearly two months, though Francona said he doesn't think the injury has affected the hitting, and Ramirez said his leg feels fine.
"My wheel is doing good," the slugger said. "I'm just going to relax. That's what I'm working on -- listening to music now to relax."
For Francona, the timing of the rest day just seemed to work out.
In addition to the dangers of facing Chamberlain's fastball, Boston's manager also considered that Sunday marked the end of a 10-game road trip.
So Sean Casey got the start at designated hitter. It was thought that Casey would take up the extra at-bats left by David Ortiz when Big Papi injured his left wrist on May 31.
But while he's recorded several pinch-hits, Sunday marked Casey's first start since June 18. Ramirez's sore hamstring has taken him from the outfield and into the DH slot, leaving Casey out of the lineup.
"I talked to Casey about that, because it has directly influenced his lack of at-bats this trip, and yeah, it's been tough," Francona said. "It would be nice to get him warm."
Samantha Newman is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.