Did the Rockies improve their bullpen enough to compete in NL West?

The Los Angeles Dodgers will take aim at their fifth consecutive National League West championship, but their biggest rival, the San Francisco Giants, will have something to say about that, especially since they've fixed their leaky bullpen with former Nationals closer Mark Melancon.

The surprise team in the division could be the Colorado Rockies. They've beefed up their bullpen and think their rotation is strong enough to allow them to play meaningful games in September.

Here's a look at pitching around the NL West as spring training camps open in Arizona and Florida:

Arizona: The Diamondbacks are counting on right-handers Zack Greinke and Shelby Miller to bounce back and anchor a young rotation. ... In his first year, Greinke had an ERA north of 4.00 and gave up home runs in 23 of 26 starts, unlike the Cy Young Award contender he can be. ... Miller, an All-Star with Atlanta in 2015, had a 6.15 ERA in 20 starts. He was sent to the minors. This spring, he's returning to mechanics he used as a Brave, and the D-backs hope that's the answer. ... The new pitcher is right-hander Taijuan Walker, acquired from Seattle. Walker has an upper-90s fastball. ... Left-hander Robbie Ray has good stuff, but he's inconsistent. ... Righties Archie Bradley and Patrick Corbin, each a high-level prospect, are in the rotation mix. ... The D-backs signed 39-year-old right-hander Fernando Rodney to be their closer. Rodney saved 25 of 28 games combined for Miami and San Diego. He had a 3.44 ERA.

Colorado: The Rockies, with the best offense in the league, think they've improved their pitching enough to contend. ... Their pitching is diversified: Ace right-hander Jon Gray is a fastball-slider pitcher with a ton of strikeouts. ... Righty Chad Bettis is effective with four different pitches. Right-hander Tyler Chatwood and left-hander Tyler Anderson are groundball pitchers with sinkers. ... Righty Jeff Hoffman, acquired from Toronto in the Troy Tulowitzki trade, has a chance to be the No. 5 starter. ... The Rockies had the highest bullpen ERA (5.13) in the league last year, but the bullpen has been fortified with the additions of right-hander Greg Holland, who had a 1.86 ERA in four seasons in Kansas City before an injury, and left-hander Mike Dunne. The bullpen also has lefty Jake McGee and righty Jason Motte. ...The closer will be right-hander Adam Ottavino, but Holland could win the job.

Los Angeles: The Dodgers are led by left-hander Clayton Kershaw, a perennial NL Cy Young candidate who has had a sub-2.00 ERA in three of the last four seasons. Last season, he was on the disabled list with a back injury, but the Dodgers still won the division. ... The Dodgers are banking that left-hander Rich Hill, 36, is worth $48 million after he posted a 1.83 ERA in six starts last year, re-energizing his career. ... The rotation also has right-hander Kenta Maeda (3.48 ERA) and prospect left-hander Julio Urias, a 20-year-old who pitched in 18 games - 15 starts - with an ERA of 3.39. ... After thinking about signing with the Nationals, the closer, righty Kenley Jansen, stayed with the Dodgers. The team signed former Giants right-hander Sergio Romo, who is set with left-hander Grant Dayton and right-hander Pedro Baez going into spring training.

San Diego: Padres manager Andy Green has been saying the team's rotation jobs are wide open, although left-hander Clayton Richard and right-handers Jhoulys Chacin, Christian Friedrich and Luis Perdomo are likely to take the first four slots. ... Perdomo, 23, a sinkerball pitcher who was a Rule 5 pick, was the Padres' best pitcher in the second half of last season. Overall, he had a 2.47 ERA in 17 starts. ... Chacin, 34, had 3.47 ERA for the Rockies in 2013 and, after two years of shoulder injuries, he combined for 34 appearances with the Braves and Angels in 2016. ... Left-hander Clayton Richard spent five seasons with the Padres, went to the Cubs as a reliever,and then returned to San Diego as a starter in August. ... Friedrich had a 4.80 ERA in 24 appearances, 23 of them starts, last season. ...Righty Brandon Maurer is the closer. He spent two seasons in Seattle's rotation and bullpen, but in his last seasons, he's been strictly a reliever. He saved 13 of 19 last season with a 4.52 ERA.

San Francisco: Madison Bumgarner leads the rotation after having his best season in 2016, setting career bests in ERA (2.74), innings (226 2/3) and a franchise-record 251 strikeouts for a lefty. ... Right-hander Johnny Cueto had a 2.79 ERA with 195 strikeouts in his first season in San Francisco. ... Left-hander Matt Moore, who had a near no-hitter, finished strong with 17 strikeouts and two runs allowed in his final two regular season starts and then pitched eight innings with 10 strikeouts against the Cubs in the postseason. ... Righty Jeff Samardzija was inconsistent, but he found his curveball and had a 2.45 ERA in his final 10 starts. ... Mark Melancon, 31, the former National whom the team wanted to keep in D.C., is the closer. He's had 51 and 47 saves in each of the last two seasons, including 17 for the Nationals in 2016.