Before Friday’s deadline to add prospects to the club’s 40-man roster that would protect them from next month’s Rule 5 draft, the Orioles had five openings. Surprisingly, they added six players — outfielder Yusniel Diaz, left-handed pitchers Zac Lowther and Alexander Wells, right-handers Michael Baumann and Isaac Mattson and infielder Rylan Bannon.

That meant someone had to go, and executive vice president/general manager Mike Elias decided that infielder/designated hitter Renato Núñez, who was eligible for arbitration, was the most expendable.

Núñez was designated for assignment. The Orioles will attempt to work out a deal for the 26-year-old, who hit 31 home runs and drove in 90 runs in 2019 and and had 12 homers and 31 RBIs in the 60-game 2020 season.

“It was a very difficult decision because he’s been such a productive member of our lineup since being claimed in 2018,” Elias said. “He’s been an important part of the club the last two years. It was a decision we didn’t make lightly, but upon coming to the conclusion that we weren’t going to arbitration with him, we felt it best to make the move today as we needed to shrink back to 40.”

The Orioles will try to trade Núñez, who could have made at least $2 million in arbitration. With a surplus of young outfielders and the return of Trey Mancini, first base and designated hitter, Núñez’s primary spots, appear to be taken.

“He’s a productive hitter, and we’ve all seen that,” Elias said. “He’s a quality player, a good hitter and a big power threat. Ours is not the ideal roster for him in terms of a fit. We have several players that play the defensive spots that he does and sort of fill that profile for us.”

Only 14 of the 40 players on the roster when Elias arrived two years ago remain.

“We’re very pleased to be graduating, so to speak, six players from our farm system onto our 40-man roster,” Elias said. “These are names that you’ve been reading about in the minor leagues the last few years.

“It’s just an important step closer to these guys contributing to the major league team. While these decisions are always difficult, one of the things that made it easier is we feel that each of these six guys will be able to contribute in 2021, if called upon by the major league team.”

Last year, Elias added four players to the 40-man roster before the Rule 5 draft — left-hander Keegan Akin, right-hander Dean Kremer, first baseman/outfielder Ryan Mountcastle and outfielder Ryan McKenna. Ten players have been added to the roster in the past two seasons.

“These are guys that have already played in Triple-A or would have played in Triple-A had we had it this year,” Elias said, referring to the canceled minor league season because of Covid-19. “While they’re not finished products, they’re developed enough to be functional members of the roster this year. I think that make these decisions easier.”

Infielder Mason McCoy and right-hander Zach Pop, who had Tommy John surgery in May 2019, were not protected. Elias said there were more players he would have liked to have added.

“Definitely one or two more that we went back and forth on as a group,” Elias said. “It’s always a tough process, and we get opinions and input from every part of the baseball ops department, coaching staff, everybody. It’s a long debate, and I think we’ve landed on the outcome that we feel gives us the best chance to retain talent in the organization.”

The least well-known player on the list is Mattson, a 25-year-old right-hander who was acquired from the Los Angeles Angels in trade for Dylan Bundy in December 2019.

“Very, very high strikeout rates, and he zoomed up three [minor league] levels in 2019,” Elias said. “He’s got attractive numbers and that’s made him attractive to other teams and attracted us to him. He was at our alternate site this summer. He’s got a 94-, 96-mph fastball with a lot of hop, and he’s got a slider and changeup that he can use on lefties.

“I think he’s the type of relief pitcher that can go more than three outs if needed, and now we’ve got a close to major league-ready, optionable relief pitcher on the 40-man roster. We may well see him get action in Camden Yards this year.”

Wells, 23, has been in the Orioles’ system since 2016, and the Australian has impressed with his control. He has walked just over one batter per nine innings in his minor league career. He wasn’t added to the 60-man player pool and has stayed in Australia during the pandemic.

“He would have been a candidate for inclusion in the alternate site,” Elias said. “We talked to him. He had a really good setup in Australia, and we decided to stick with that. He’s likely to pitch winter ball over there as well.

“This is a guy that flies a little bit under the radar in our system, but his minor league success has been crazy so far. He’s dominated. He has elite command, and he’s got a premium curveball and a nice cutter/slider that he’s been working on.

“The reason we were determined to protect him this time around is that we view him as a potential starting pitcher. That’s a valuable asset. This is a guy that’s knocking on the door right now. If called upon this year, he could potentially come up and help the team. We didn’t want to risk losing him.”

Bannon was acquired in the same trade that brought Diaz, Kremer and Pop from the Los Angeles Dodgers for Manny Machado in July 2018. He plays second and third.

“He’s going to be in the mix,” Elias said. “He’s on the roster, and he’s going to be coming to major league spring training, and I imagine that we’re going to have competition for any number of jobs in the infield. He’s a guy that can move around.

“If you ask what his position is, you might get some different opinions, whether that’s second base or third base, which I think is a good thing. It’s interesting, but also it’s about the bat with him. He’s had a really terrific minor league career. He’s got power. Our hitting coaches that worked with him at the Bowie camp really liked him. The same in Instructional League.

“I think he was a good get in the trade in 2018. While he wasn’t the headliner in that trade, we value him highly and I have very little doubt that had he been exposed in this draft, he would have been taken. He was always somebody that we were counting on getting into our infield mix for 2021 and if he ends up spending the lion’s share of time in Triple-A, that will be good for him, too.”