This is the final installment of a seven-part Around the Horn series that features a position-by-position look at the A's projected starters and backup options heading into the 2014 season. Today's focuses on the bullpen.

OAKLAND -- Bob Melvin may soon have to refine a statement he made on multiple occasions last year.

The A's skipper would often comment on how his 2013 squad boasted the best bullpen he'd ever managed. Now, it appears he has an even better one under his watch.

Yes, Melvin will be without Grant Balfour, who tucked away the 62 saves he compiled in Oakland the last two years and rejoined the Rays on a two-year deal, and also without valuable lefty Jerry Blevins, who was traded to the Nationals. But Melvin's bosses have fortunately spent the majority of the offseason atoning for these losses with big gestures.

Balfour has been replaced by All-Star Jim Johnson, whose 101 saves since the start of 2012 lead the Majors, and he'll not only be flanked by returning setup men Sean Doolittle, Ryan Cook and Dan Otero, but newcomer Luke Gregerson as well.

Gregerson has proved to be one of the most reliable setup men in baseball in recent years, and in 2013, he posted a 2.71 ERA over 66 1/3 innings. He has a 2.88 ERA and 352 strikeouts against 107 walks in 363 relief appearances over his five-year big league career.

"We had some spots we needed to fill with some of the guys that we lost," general manager Billy Beane said this winter. "I think we addressed the areas we needed to, and in some cases, I think we've even upgraded, particularly when you look at the bullpen, with the addition of Johnson and Gregerson."

Stocking up didn't stop there.

Shortly after acquiring Johnson and Gregerson, the A's took a risk by trading lefty Brett Anderson to the Rockies for another southpaw in Drew Pomeranz, a former first-round Draft pick. Pomeranz will be stretched out as a starter in Spring Training, but like Tommy Milone, he could end up in the bullpen as a long-relief option.

Pomeranz struggled with command issues while pitching within the hitter-friendly walls of Coors Field for a home ballpark, turning in a 5.20 ERA in 34 big league appearances, with 115 strikeouts against 70 walks in 136 2/3 innings for the Rockies. He also dealt with a variety of ailments that are now no longer of concern, and Beane sees plenty upside in the lefty.

"Colorado is a very unique environment for pitchers," Beane said. "He's only 25, and a lot of people still think very highly of his abilities, and we felt it was a good time to acquire him."

Another southpaw in the mix for a bullpen spot is Fernando Abad, who came in a deal with the Nationals. And by July, one of the most prominent left-handed relievers in the game is expected to join the A's bullpen.

Eric O'Flaherty, who is coming off Tommy John surgery, was signed to a two-year, $7 million deal by Oakland just last week. He was limited to just 19 games with the Braves last year before succumbing to surgery, but the lefty gave Atlanta 13 wins and a 1.99 ERA over 295 appearances in a setup role over the past five seasons.

When considering the last three seasons, no other reliever with at least 125 innings compiled a better ERA than O'Flaherty, who posted a 1.45 mark in 161 appearances over that span. In that time, he held opponents to a .220 batting average, including .156 against left-handed hitters.

From the right side, seemingly already stacked, Oakland will also keep watch on Jesse Chavez, Fernando Rodriguez and recently acquired Josh Lindblom to fill out its relief corps.

"I thought we had a good bullpen last year, and I think these moves have a chance to make it even possibly better," said Beane. "The best way to help out your starting rotation is to fill up your bullpen."