Manager Bryan Price said that Hoover, who has only five career saves, will get the first chance at holding down the job during spring training. Hoover, 28, has been used in the setup role, making him the top candidate to pitch the ninth inning this season.
"It is fair to say that he will be the closer," Price said on Thursday, when pitchers and catchers reported to camp. "He's earned it. He is going to make our major league bullpen. There are not a lot of defined roles in our bullpen. Unless we make a roster move to bring in a definitive closer, it is his job to lose."
Chapman has been the constant in the bullpen for the past few years. He became part of the Reds' rebuilding overhaul in the offseason and was traded to New York for prospects. The move left no one on the roster with experience closing major league games.
Hoover got seven save opportunities last season when Chapman wasn't available and blew six of them, underscoring the difference between pitching the eighth and the ninth innings with a game on the line. Hoover was 8-2 overall with a 2.94 ERA in 67 games, second most on the staff.
In 2014, Hoover went 1-10 with a 4.88 ERA. He lost 10 straight decisions, a club record for a reliever, and tied the club mark with 10 losses overall by a reliever.
He and Jumbo Diaz, who also was used in a setup role, were the top two candidates on staff to move up to the closer's role. Hoover has been getting ready to win the job in spring training.
"I'm honored that it is my job to lose," Hoover said. "There is a lot of time left in spring training, but I'm excited to try and lock that job down. My approach was the same in the offseason. I worked with our strength coach. We got a little more advanced in our movements. I'm a lot stronger than I was a year ago."
The pitching staff is the biggest question in camp. Anthony DeSclafani and Raisel Iglesias pitched well enough as rookies last season to earn spots in the rotation. Homer Bailey, the only veteran starter, had Tommy John surgery last May and isn't expected back for at least a month into the season.
The bullpen also is a work in progress with Chapman gone. In addition to the closer and setup roles being in transition, numerous young pitchers are competing for spots to fill out the relief staff.
"It's exciting having the young talent around," Hoover said.
In other injury news, shortstop Zack Cozart (knee) and center fielder Billy Hamilton (shoulder) got permission from Major League Baseball to work out with the pitchers and catchers. Both are coming off surgery last season.