BALTIMORE -- The Red Sox were without Michael Chavis for Sunday's rubber game against the Orioles after the infielder left Saturday's 17-6 blowout win over Baltimore with lower back spasms in the fifth inning.

Manager Alex Cora wasn't overly worried about the rookie, who arrived at the ballpark early Sunday for treatment. Cora is optimistic Chavis will be ready to return for Monday’s series-opener in Tampa Bay, and Chavis reassured him before the series finale in Baltimore he was feeling fine.

Marco Hernandez -- who replaced Chavis on Saturday -- started at second on Sunday and Brock Holt -- who, according to Elias, became the first Red Sox player ever to play first, second and shortstop in the same game Saturday -- slid over to start at first.

"Chavis is OK," Cora said. "His back got tight a little bit, so he'll come tomorrow, get some treatment early. ... He should be fine."

For his part Saturday, Chavis went 0-for-2 in the onslaught but he made what Cora said was one of the more important plays on the night. He hustled on a ball in the infield that forced Baltimore's Richie Martin into an error. Two batters later, Mookie Betts belted a two-run shot that regained a Boston lead after the Orioles had stormed back to make it 5-5 the half inning prior.

"That changed the complexion of the game," Cora said.

For the season, Chavis is hitting .255/.329/.450 with 16 homers, 52 RBIs and 41 runs scored -- with the latter two numbers leading all American League rookies.

Moreland could return against Rays

First baseman Mitch Moreland’s return could come as soon as Monday in Tampa Bay depending on how he feels after his third rehab game with Triple-A Pawtucket Sunday, Cora said.

“This is a guy we need,” Cora said. “We’ll talk to him after the game and see how he feels. If he needs a little bit more, he’ll get it. If not, he’ll be ready for Tampa.”

Moreland will play first for the third game this weekend after playing all of Friday’s game and seven innings Saturday. With Pawtucket hitting the road next, Cora hopes Moreland will feel well enough to re-join the Red Sox for a pivotal series against the Rays. Otherwise, an extended rehab stint with Double-A Portland is in the cards.

So far this weekend, Moreland is 0-for-5 with a walk. He has felt good after games and is seeing plenty of lefty-lefty matchups while putting together decent at-bats.

“He has plenty of at-bats, so that’s the most important thing,” Cora said. “He’s got pitches, seeing the ball. We’ve seen a lot of guys go 0-for-20 down there and then they come here and they start raking. For me, the quality of the at-bats are important, and so far he’s facing a lot of lefties, staying back, driving pitches. That’s good.”

Benintendi’s struggles taking their toll

Andrew Benintendi is just 5-for-31 and slashing .161/.316/.258 in eight games since the All-Star break. Most concerning for Cora is the mental impact it’s taken on the young outfielder.

“It’s wearing on him,” Cora said of Benintendi, who was held out of the lineup Friday and went 0-for-4 Saturday with two walks and three strikeouts -- one against Orioles utilityman Stevie Wilkerson. “Like yesterday, striking out against a position player -- I don’t care who you are, you are going to be down. You can see him, he’s frustrated. It’s our job to stay with him and help him through this process.”

Strikeouts have been the thorn in Benintendi’s side. He’s done so 11 times since the All-Star break and now sits second for the Red Sox with 93 on the year.

“If you look, there’s a lot of strikeouts. Something that wasn’t on the radar,” Cora said. “He’s still walking, but it seems like he’s not going straight to the ball. He’s not been able to hit the ball to the opposite field a lot.

“Early in the season down in the zone chasing and now he’s up. He’s been frustrated. You see it. Just have to stick with him. … The way to see it, he is a pure hitter, we know he can hit. Just have to continue to talk to him and get him to a spot where he’s comfortable. When he’s comfortable he’s one of the best hitters that we have.”