BALTIMORE — If the New York Yankees are to continue their late-season push to snag a spot in the postseason, they need to stay healthy in September.

Toward that end, the month has gotten off to a rocky start.

Rookie right-hander Chad Green left Friday night’s game with elbow pain, and the Yankees surrendered four home runs in an 8-0 loss to the Baltimore Orioles.

Green was making his eighth start of the season, and New York can only hope it wasn’t his last. The team should have a better idea of the severity of the injury on Saturday.

“Obviously he needs to have an MRI on his right elbow,” manager Joe Girardi said.

The MRI has become an unwanted necessity for the Yankees. Outfielder Aaron Hicks had an MRI on his right hamstring Thursday, and the results dictated that he will miss at least a week.

Green was struggling during Baltimore’s six-run second inning when he suddenly found it difficult to extend his right arm. Minutes later, he walked off the mound with head athletic trainer Steve Donohue.

“It wasn’t any particular pitch or anything. Just something I wasn’t used to,” Green said. “Hopefully ‘s nothing too serious, but we’ll see.”

Green (2-4) allowed four runs and five hits in 1 2/3 innings.

Pedro Alvarez and Chris Davis hit two-run homers in the second inning before Mark Trumbo capped the uprising with his major league-leading 41st long ball. Manny Machado added a two-run shot in the fourth.

“We weren’t able to keep the ball in the ballpark, and it’s how this club is extremely dangerous,” Girardi said.

Baltimore leads the majors with 213 home runs, including 117 at home.

When Alvarez went deep, the Orioles became the 19th team in big league history to have six players hit at least 20 in the same season. Alvarez joins Trumbo, Machado (33), Davis (33), Adam Jones (24) and Jonathan Schoop (21).

Dylan Bundy (8-5) allowed two hits and four walks over 5 2/3 innings. In his previous start, the right-hander took the loss Saturday at Yankee Stadium after giving up five runs and seven hits in four innings.

“Bundy threw the ball well and we just got in a big hole from the get go and couldn’t get out of it,” said Brett Gardner, who had one of New York’s two hits.

It was only the third win in eight games for the Orioles, who started the day tied with Detroit for the second AL wild-card slot.

New York fell 3 1/2 games behind Baltimore. The Yankees came to town with a streak of four straight series wins.

After leaving the bases loaded in the first inning, the Orioles batted around in the second. Jones singled in a run before Alvarez launched a drive that landed on Eutaw Street beyond the 25-foot scoreboard in right field. Green left after walking Machado, and Davis greeted Nick Goody with a home run.

Trumbo followed by going deep on an 0-2 pitch, the 17th time this season the Orioles have hit back-to-back home runs.

Two innings later, Machado connected off Kirby Yates for an 8-0 lead.

WELCOME ABOARD

Yankees: New York recalled several players from its minor league system, including Goody and RHP Jonathan Holder, who threw a scoreless inning in his major league debut.

Orioles: Obtained in separate transactions Wednesday, OFs Michael Bourn and Drew Stubbs made their debut with the Orioles as defensive replacements. … The Orioles recalled RHP Tyler Wilson, LHP Jayson Aquino and C Caleb Joseph from Triple-A Norfolk.

TRAINER’S ROOM

Yankees: Girardi said of Hicks: “He’s a guy that’s going to be out for a while.” The injury occurred Wednesday night.

Orioles: RHP Chris Tillman (right shoulder bursitis) has been penciled in to return Sept. 11 in Detroit. … RHP Darren O’Day (rotator cuff strain) will throw off a half mound Sunday. … Jones returned to action after missing a week with a strained left hamstring.

UP NEXT

Yankees: CC Sabathia (8-11, 4.31 ERA) vies for his 20th career win against the Orioles on Saturday night. He’s 19-9 vs. Baltimore but 1-2 this season, including a loss last Sunday.

Orioles: Kevin Gausman (6-10, 3.73) seeks to win his fourth straight start, a streak that includes a 5-0 victory over Yankees on Sunday in which he struck out nine in seven innings.