OAKLAND -- The A's will begin the season with an eight-man bullpen, foregoing a fifth outfielder in favor of additional relief behind a young starting staff.
Right-hander Frankie Montas and lefty Daniel Coulombe were picked to fill out the bullpen, while Jaff Decker was the odd man out of the outfield. Mark Canha will serve as the backup center fielder.
"It just looked like early in the season we have some young starters we're trying, to an extent, trying to protect," A's manager Bob Melvin said. "You never know what kind of innings you're going to get out of the complete group, so when you have somebody like Frankie who can give you multiple innings and be effective, this is the route we're going at least to start."
Montas was one of three pitchers -- along with the club's No. 3 starter, Jharel Cotton -- the A's acquired from the Dodgers for outfielder Josh Reddick and starter Rich Hill last summer. The right-hander, ranked as Oakland's No. 5 prospect, showcased his elite velocity this spring and produced telling results, allowing just one run in 11 2/3 innings with 13 strikeouts.
The A's, despite still viewing him as a starter in the long term, could not ignore the performance.
"It's kind of a unique arm," Melvin said. "A guy that's really a starter yet has the ability to give you length."
Montas said his first call upon hearing the news was to his mom, Gressel, in the Dominican Republic.
"She was screaming and crying," Montas said. "I said, 'It's OK, you're going to be here soon with me.'"
Adding Montas to the 25-man roster meant sacrificing a fourth bench option. Melvin said his conversation with Decker, hitting .313 this spring, "was the hardest one."
"He did everything he could do to make a team," Melvin said. "Had we not gone with eight relievers, he would've been on the team, and I told him that. I would be surprised if he is not here at some point in time."

"I felt like I put myself in a good position to help this team and be a part of it, but things happen," Decker said. "You got to believe that you can be here and you can play, and when you get the opportunity, take advantage of it. Hopefully all goes well and I can be back up here and help them win."
In other news, Melvin declined to name a closer ahead of Opening Night, insinuating he could begin the season Monday with more than one in mind. Veteran right-handers Ryan Madson and Santiago Casilla are presumably at the top of the list.
"We talked about the bullpen dynamic amongst the group, and we'll play it by ear," he said. "I'm not going to say, 'This is the guy that's going to close.' We'll see come Opening Day who's out there for the ninth inning, and it might have a little bit to do with matchups."
Worth noting
Right-hander Sonny Gray (lat strain) threw all of his pitches in a flat-ground session Saturday morning and could soon throw off a mound. Barring any setbacks, Gray is expected back in the rotation by the end of the month.
He's one of five players who will begin the season on the disabled list, along with pitchers Chris Bassitt (Tommy John) and Daniel Mengden (foot surgery), infielder Joey Wendle (strained shoulder) and outfielder Jake Smolinski (shoulder surgery).