BALTIMORE—The long-awaited debut of Ryan Mountcastle was uneventful and uplifting at the same time.

Mountcastle, a prospect Oriole fans have been eager to see since last season when the was the International League’s Most Valuable Player, finally arrived on Friday night.

He was hitless in two at-bats, walked twice, scored a run and caught two fly balls in the Orioles’ 8-5 loss to the Boston Red Sox, their sixth in a row.

The Orioles, who are 12-14, matched their six-game skid of September 3-10, 2019.

Mountcastle began the night by running out of the dugout to take the field only to realize that his teammates hadn’t followed him. He stopped when he realized he was alone, laughed and then waited for the rest of the Orioles to join him.

John Means started for just the fourth time of the year, and lasted three innings. In his last start on Sunday, he didn’t make it through the first inning, allowing three runs.

Again, he gave up three runs, but made it through the third inning.

“I felt really good tonight, and I felt every pitch was working except for the changeup,” Means said. “The story of this year, all my pitches look really good except for my changeup.”

Xander Bogaerts’ sixth home run of the season, his second in two nights, gave Boston a 1-0 lead in the second. J.D. Martinez hit a long home run to center that measured 431 feet, a two-run shot, in the third.

Means allowed three runs on four hits in three and was relieved by Jorge López, who did the same on Sunday.

Lopez gave up a 447-foot three-run homer to Rafael Devers in the fifth and a two-run single by Michael Chavis in the sixth to run Boston’s lead to 8-0.

“We got beat by changeups,” Orioles manager Brandon Hyde said.

After the Orioles left two runners on in the first, Mountcastle led off the second and walked. He was quickly erased when catcher Chance Sisco hit into a double play.

Two batters after Kevin Pillar made a spectacular diving catch on Pedro Severino foul ball in the fourth, Mountcastle struck out against Colten Brewer.

Brewer, making just the second start of his major league career, pitched four scoreless innings, giving up three hits.

One of the hits was Anthony Santander’s first-inning single that ran his hitting streak to 16 games, longest in the major leagues.

Mountcastle flied to right, ending the sixth and walked for the second time in the eighth.

“His debut, two walks,” Means said. “I think he might have walked 10 times in his whole minor league career and up here he has two walks in his first game, so I was giving him crap about that. But he’s going to be so good up here for a long time, so I have nothing but good things to say about him.”

Boston’s Darwinzon Hernandez pitched two shutout innings, and Josh Osich gave up back-to-back home runs to Pat Valaika and Cedric Mullins in the seventh. It was Valaika’s fourth and his second in two games, and Mullins’ first since September 18, 2018. It was Mullins’ first extra-base hit batting right-handed.

“It’s always fun playing with Ryan,” Mullins said. “I’ve been playing with him since Short-Season A ball, and we always have a great time.”

After Pedro Severino and Mountcastle walked in the eighth, Sisco hit a three-run home run against Osich, his fourth of the season, to cut Boston’s lead to 8-5. It was the second homer he’s hit against a left-hander.

Mountcastle walked 24 times for Triple-A Norfolk in 2019 and had just two two-walk games.

“I thought those were two good at-bats,” Hyde said. “Couple of good walks for him tonight.”

Mullins had three hits, his season high, and along with Mountcastle, Santander and Austin Hays, is giving the Orioles four interesting outfielders to look at for the remainder of 2020. Hays, who’s on the injured list because of a fractured rib, should be back in a week or two, Hyde said.

“We’re young. We’re inexperienced,” he said. “It’s fun to see talented guys out there, guys with tools. We’ve talked a lot about what Santander has done so far, loved the year he had last year and continued to really be an impact player in our game.

“Cedric has had some really nice at-bats this last week where he’s bunted for some hits. He’s played some nice defense, aggressive on the bases. He’s playing with some confidence, which is nice to see.

“It’s tough losing Austin. We saw what Hays did last September, and I think he was on track to start doing that again. That’s why it’s disappointing for him to miss this time because he’s a big part of our team.

“I like the package he brings, and the way he plays defense, competitiveness to his at-bats. He’s a really competitive guy. We’re on the right track, getting talented guys in the system. Some of these guys are starting to get to the big leagues, and probably getting a lot of playing time.”

Mullins is 10-for-21 (.476) since Sunday.

“I’d say the work I put into the offseason has made tremendous strides in my game in general,” Mullins said. “Just seeing when there’s an opportunity for me to just get on base any chance I get. Like today, I hit the long ball, but when we got to the point in the game when we needed runners I was able to lay the bunt down.”