ATLANTA — Tyler O’Neill, the Orioles’ key offensive signing last winter, was activated off the injured list and is set to play just his 25th game of the season on Friday as Baltimore opens a three-game series against the Braves.

To clear a roster spot, Dylan Carlson was optioned to Triple-A Norfolk on Thursday.

O’Neill was placed on the injured list May 18 with a shoulder impingement and at first progressed quickly, going on a rehab assignment the first week of June. But he still wasn’t 100%, and was given a cortisone shot before the team decided to shut him down and bring him back to Baltimore. He then received a platelet rich plasma injection, which he said left him sore for a few days but eventually provided some relief.

“I feel a lot better physically,” O’Neill said. “I was able to play some minor league games, I recovered well through every game, starting to find the barrel again. Just really looking forward to joining these guys again, you know, playing some baseball every day.”

O’Neill, who was signed to a three-year, $49.5 million deal (with an opt-out after the first year), was the first player to receive a multi-year guaranteed free agent contract from general manager Mike Elias. It was clear that he was seen as the replacement for Anthony Santander, who signed a five-year, $92.5 million contract with the Blue Jays. O’Neill, a right-handed hitter, was also expected to help against left-handed pitching, an area the Orioles consistently struggle with.

Yet O’Neill’s season has been riddled with injuries. This was his second stint on the injured list this year. O’Neill first missed time with neck inflammation and then with the shoulder impingement. In the time he has been healthy, he hasn’t provided the boost the Orioles were hoping for, hitting .188 with two home runs.

“It’s been frustrating for sure,” O’Neill said. “Just trying to focus on rehab and crushing what I can do on a day-to-day basis but really thankful for that dedication that I’ve put in the last segment of time. Obviously we have a really good medical staff here, just thankful for everybody on board to get me to the position I am now.”

Without O’Neill, the Orioles have primarily played Ramon Laureano in right field, Cedric Mullins in center and Colton Cowser in left. Now that O’Neill is back in the mix, they could stick with the same defensive alignment and use O’Neill as the designated hitter, or have O’Neill play some right field again and either bump someone else out of the lineup or rotate off days.

On Friday, O’Neill will DH and bat eighth. He is expected to play in the field on Saturday, interim manager Tony Mansolino said.

“We missed this guy for a while,” Mansolino said. “He’s had a great career, it’s a big bat for us that Mike signed and brought in. We need this guy.”