KANSAS CITY -- The Royals made several roster moves on Tuesday ahead of the deadline to protect players from the Rule 5 Draft, selecting right-hander Alec Marsh, outfielder Diego Hernández and catcher Freddy Fermin to the 40-man roster.

In corresponding moves, lefty Jake Brentz, right-hander Nate Webb and outfielder Brent Rooker have been designated for assignment.

The Royals are hopeful they can bring back Brentz on a Minor League deal, given that he’s rehabbing from Tommy John surgery and won’t be back on the mound until the second half of 2023. They did the same thing with lefty Richard Lovelady last year, non-tendering him then signing him to a Minor League deal while he finished his Tommy John rehab throughout 2022.

The Royals also announced Tuesday that first baseman/outfielder Ryan O’Hearn agreed to a contract for 2023, avoiding arbitration for the second year. The deal is worth $1.4 million with $250,000 in performance bonuses, a source told MLB.com. O’Hearn made $1.3 million this past season.

O’Hearn hit .239/.290/.321 with an 73 OPS+ in 2022, but he only played in 67 games despite being on the roster the entire year. He has underperformed and seen limited playing time, but the Royals remain intrigued by his power potential, especially with the shift limits expected to help out left-handed batters next season.

Kansas City’s roster is at a full 40 players. Teams had until 5 p.m. CT on Tuesday  to add eligible prospects to their 40-man roster to protect them from the Rule 5 Draft in December. Clubs that pick a player in the Draft must pay $100,000 to the club from which said player was selected. Rule 5 Draft picks are assigned directly to the drafting club's 26-man roster and must be placed on waivers to be removed. Should the player clear waivers, he must be offered back to his previous team for $50,000.

Players signed at age 18 or younger are eligible for the Rule 5 Draft within five seasons of being signed. Players who signed at age 19 or older need to be protected within four seasons.

Marsh is the Royals’ No. 19 prospect and posted a 6.88 ERA across 124 1/3 innings in Double-A and Triple-A this past season. He stayed healthy the entire year, a good sign after being sidelined for most of the ’21 season with injuries and missing out on the ’20 pandemic season. The 24-year-old struck out batters at a 27.4% clip at Northwest Arkansas, displaying the elite, filthy stuff he’s had since the Royals drafted him as their Competitive Balance Draft Pick in 2019.

While Marsh had a 1.62 WHIP and batters hit .279 against him, he still flashed tons of potential and is part of the Royals’ young core of pitchers they plan to build around.

Hernández, the club’s No. 20 prospect, is 21 years old and still needs significant development before he’s a consistent Major League player. But his speed, range and impressively strong throwing arm would play in the Majors right now, and a team could use him off the bench, leading the Royals to add him to the roster Tuesday -- much like they did last year with shortstop Maikel Garcia.

Hernández slashed .284/.347/.407 in High-A and Double-A this past season and saw a jump in power, hitting nine home runs after entering the year with just two career homers.

Fermin was the most intriguing 40-man addition on Tuesday, a 27-year-old catcher who debuted in the big leagues in 2022 during the Royals’ trip to Toronto without 10 of their regular players. Fermin is known more for his defense than his bat, but he did see an offensive jump this season, posting an .845 OPS across 87 games at Triple-A Omaha. The Royals are looking for a backup catcher this offseason, so Fermin could fill that void if the club doesn’t add to the position.

Among the prospects not added Tuesday, lefties T.J. Sikkema and Anthony Veneziano stand out. Sikkema, the Royals’ No. 16 prospect, was part of the Andrew Benintendi trade in July and posted a 4.83 ERA across High-A and Double-A in 2022.

Veneziano had a 5.72 ERA in Double-A this past season and saw his strikeout rate dip, but scouts still see potential with his 6-foot-5 frame and mid-90s fastball.