PHOENIX -- The Oakland Athletics continue their quest to do more with less than the rest of the American League West, but with even more star power in the division, will the low-payroll club be able to defend the West title they earned each of the past two seasons?

Oakland, unable to add pieces like second baseman Robinson Cano (who signed with Seattle) or center fielder Shin-Soo Choo (signed with Texas) or first baseman Prince Fielder (acquired by Texas in a trade), went heavy on bullpen additions this winter. After two years of putting together the most versatile group of position players in the game, the A's now have what might be the deepest bullpen, trading for closer Jim Johnson and set-up man Luke Gregerson and signing lefty Eric O'Flaherty (who is coming back from Tommy John surgery).

Will a strong bullpen be enough to make up for any shortcomings with a young rotation? Bartolo Colon, 40, left as a free agent, and longest-tenured Oakland starter Brett Anderson was traded to Colorado. Right-hander Jarrod Parker, 25, is the most likely candidate to start on Opening Day. Right-hander Sonny Gray, a good bet for the No. 2 spot, is 24.

The A's signed Scott Kazmir to a two-year, $22 million deal to provide some experience, but the left-hander was almost out of the game altogether just two years ago. Is he the pitcher who won 10 games for Cleveland last year? Or the one who had an ERA of nearly 6.00 for the Los Angeles Angels in 2011 and was pitching in independent ball in 2012? The A's point to his strong finish -- he had a 2.57 ERA in five starts from Sept. 1 on -- but Kazmir still probably does not quite qualify as a sure thing.

Do the A's have enough offensive firepower to contend with the big names playing for division rivals? Nearly the entirely lineup is back, with the exception of DH/outfielder Seth Smith, sent to San Diego for Gregerson, and fourth outfielder Chris Young, who left as a free agent.

Many with Oakland believe the A's got better offensively with the addition of fourth outfielder Craig Gentry, who should see plenty of playing time. John Jaso, back from a concussion, led the team in on-base percentage last year and he could see some time at DH. Most important for the A's, they believe left fielder Yoenis Cespedes will bounce back from a rough second season.

Cespedes and right fielder Josh Reddick remain question marks, though, after disappointing 2013 seasons at the plate. Cespedes showed signs of emerging from his slump the final month and he said before spring training that he cut down his swing to ensure more contact. Reddick never really got on track, but he played much of the year with a wrist injury that affected his production.

One big and pretty fun question for Oakland this spring: Can hotshot prospect Addison Russell make the team on Opening Day? The 20-year-old shortstop is Oakland's best position-player prospect since third baseman Eric Chavez 15 years ago, and he's widely expected to be called up at some point this year, though midseason or thereafter is more reasonable should Russell have good success early on at Double-A Midland and Triple-A Sacramento.