The Orioles promoted one of their top position player prospects, Ryan Mountcastle, for Friday night’s game against Boston.

They also placed first baseman Chris Davis on the 10-day injured list because of left patellar tendinitis, an injury or inflammation of the tendon that connects the kneecap (patella) to the shinbone (tibia). The move is retroactive to Thursday.

Mountcastle has been at the Orioles’ alternate site at Bowie playing left field.

“I just tried to get all my work in at Bowie,” Mountcastle said in video conference call. “Just hoping I’d get my shot and just be ready for when I did. We did a lot of good stuff down there, and I feel prepared for the games coming up.”

Mountcastle is batting sixth and playing left field. Manager Brandon Hyde said that he expects Mountcastle to play both left and first base.

“I’m going  to play him a lot,” Hyde said. “Give him a lot of at-bats for the next 30-plus games. I know he’s excited to be here, and I look forward to watching him play.”

Drafted as a shortstop with the 36^th overall pick in the 2015 draft, Mountcastle was moved to third base in 2017, and last year played both first base and left field for Triple-A Norfolk, where he was named the organization’s top position player and the International League’s Most Valuable Player.

“I feel a lot more comfortable in the outfield now,” Mountcastle said. “It’s a new position for me, still. I feel I did enough work down there to be serviceable up here in the big leagues and help them win.

“I was trying to work on some plate discipline stuff at Bowie, too, and I feel like I did a good job with that as well.”

The 22-year-old Mountcastle hit .312 for Norfolk with 25 home runs and 83 RBIs.

“We feel comfortable with the work that he’s put in at the secondary site,” Hyde said “This isn’t a snap decision. This is something we’ve talked about a lot, and we felt like today was the day. He’s been playing well down there, getting a lot of work in. The coaches down there are really impressed with the work he’s put in, the improvement he’s shown not only defensively, but at the plate.”

Mountcastle is ranked as the No. 57 prospect in Baseball Prospectus and No. 94 by MLB.com.

Fans have been clamoring for Mountcastle’s recall, and he’s been aware of that.

“I was getting some good love on social media,” Mountcastle said. “And seeing that is really excited for the fans and myself, seeing that they want me up there. That was pretty cool to see.

“I didn’t know if or when I’d get the call. I was trying to stay prepared every day. I thought there was a pretty good chance I’d get the call this year at some point.”

Expectations are high for Mountcastle, and he’ll try not to put pressure on himself.

“I’m just going to go out there and play my game and not try to do that much,” Mountcastle said. “I’m not going to try to hit balls 800 feet. I’m just going to try to stay with my approach and do what I can do.”

Hyde wants Mountcastle to relax before his debut.

“I don’t want him to think he’s got to do anything different than he would in a normal game,” Hyde said. “Today’s going to be a big day. He’s going to have butterflies. He’s going to be nervous. I want him to feel as relaxed as possible.

“We’ve all been through guys making their debuts, prospects making their debuts. Some go well. Some don’t. Some figure it out later than others. I just want him to be as comfortable as he can possibly be. I want him to feel like he belongs here. I think he’s a confident guy. I think half the battle is to feel like you belong here. I think he feels that way.

“I just want to play his game and be a part of the team and not feel like he has to carry any load. Four good at-bats a night, continue to work on his defense and just be part of our lineup and part of the team.”

Davis is batting .122 (6-for-49) with one RBI in 15 games.

Hyde said that Davis could be out for longer than 10 days.

“He’s got some knee soreness,” Hyde said. “He mentioned it to me about four or five days ago and we felt like the right thing to do was to put him on the IL to continue to get treatment…I feel like the right move was to put it on the IL to give the knee some rest.”

Notes: Hyde said he hoped that shortstop José Iglesias, who’s on the injured list because of a sore left quadriceps muscle, will be ready to play on the road trip to Tampa Bay and Buffalo, which begins on Tuesday. Iglesias is eligible to return on August 26th … Centerfielder Austin Hays, who is on the IL because of a fractured rib, could be back “during the next week to two weeks. I’m not really sure on his timetable. Still feeling the rib a little bit,” Hyde said … Right-handed pitcher Chandler Shepherd, was outrighted to the Bowie alternate site on Thursday after passing through waivers. The 60-man roster is at 59.