8-man bullpen to open season

Oakland will enjoy a supersized bullpen to open the season, but the identity of the team’s closer remains guesswork.

With a young and, in the final three spots, untested rotation, the A’s elected to keep eight relievers, including hardthrowing Frankie Montas, who can serve as a long reliever. “I have a big smile on my face today,” Montas said.

Manager Bob Melvin said he spoke to the team’s relievers about their roles Saturday, but he didn’t share specifics with reporters.

“We talked about the dynamics amongst the group, and we’ll play it by ear,” Melvin said. “I’m not going to say, ‘This is the guy who’s going to close.’ We’ll see come Opening Day who’s out there for the ninth inning.”

The A’s have four men with extensive closer experience: Santiago Casilla, Ryan Madson, Sean Doolittle and John Axford. Matchups will be a consideration, Melvin said.

Case in point: All seven of Madson’s blown saves last season came against the AL West, and he had a 5.73 ERA and .331 opponents average against the division. Against everyone else, Madson had a 1.42 ERA and a .165 opponents average. Seven of the A’s first eight series this year are against AL West teams.

It’s likely the team will elect to go with a three-man bench — Mark Canha, utility infielder Adam Rosales and catcher Josh Phegley — for just a short time. Canha will be the backup center fielder.

Melvin said it was difficult to send out outfielder Jaff Decker, who hit .313 and played well defensively. “He did everything he could do to make the team,” Melvin said.

Decker has an out in his contract with the A’s on May 1, so he almost certainly will be recalled before then.

Briefly: Right-hander Sonny Gray threw a flat-ground session for the first time since incurring a lat strain, and he could be throwing off the mound in the next several days. ... According to general manager David Forst, the A’s have re-signed left-hander Ross Detwiler, who will report to Triple-A Nashville.