CINCINNATI -- Ahead of Tuesday’s deadline to protect players from exposure to next month's Rule 5 Draft, the Reds added two players to their 40-man roster.

Right-handed reliever Luis Mey and infielder/outfielder Tyler Callihan were protected, and Cincinnati also announced the signing of Nick Martinez to his one-year, $21.05 million contract after the righty accepted the qualifying offer. The moves brought the Reds’ 40-man roster to 39 players.

That meant players like pitching prospect Jose Acuna were left exposed for other clubs to select next month.

“Obviously, we have to leave some room to be able to sign free agents, to be able to make trades. We have one roster spot open with Martinez coming back," Reds president of baseball operations Nick Krall said.

Neither Mey nor Callihan is currently ranked among MLB Pipeline's Reds Top 30 Prospects. No Top 30-ranked players in the organization needed protection this year.

The Rule 5 Draft is scheduled for Dec. 11 during the Winter Meetings in Dallas.

Mey, 23, split the 2024 season between High-A Dayton and Double-A Chattanooga, and he had a 3.44 ERA and nine saves over 40 relief appearances. After the season, he starred for Glendale in the Arizona Fall League with 8 2/3 scoreless innings over eight games while notching six saves and being named the AFL's Reliever of the Year.

During the fall, Mey was the only AFL pitcher to have velocity over 100 mph, according to Statcast. He did it 30 times and topped out at 101.8 mph.

“He’s got a chance to be a dominant back-of-the-bullpen-type guy," Krall said. "He’s going to come in with a chance to compete [for a 26-man roster spot] just knowing he ended up in Double-A. Who knows what’s going to happen when we get into camp? He showed he could throw strikes in the Fall League. He’s really progressed from where he was earlier in the year all the way through the end of the Fall League.”

Callihan, 24, batted .276 with a .788 OPS, nine home runs, 27 RBIs and 22 steals over 73 games with Chattanooga and Triple-A Louisville last season. His season was interrupted when he missed two months from June-August with a hand injury.

In the AFL, Callihan batted .263 with a .762 OPS, two homers and 10 RBIs in 19 games for the Desert Dogs. He was a third-round selection in the 2019 Draft and was once a Reds Top 30 Prospect. But injuries and struggles knocked him backwards.

“He was a slow starter in pro ball. He’s really started to break out," Krall said. "This year, went to Double-A and struggled a little bit with injuries and missed some time in the middle of the season. When he came back, he played really well. Plays a good second base and is learning to play left field. He’s got a chance to be a solid Major League contributor."