VIERA, Fla. -- Braves manager Fredi Gonzalez's bullpen appears to be pretty well set. But with some uncertainty surrounding right-handed reliever Jordan Walden's back, Gonzalez is keeping an open mind about which relievers could be on his Opening Day roster.

Closer Craig Kimbrel, Eric O'Flaherty, Jonny Venters, Luis Avilan and Cristhian Martinez are the most likely candidates to be in the bullpen at the start of the season. Without providing any guarantees, Gonzalez is also expecting sidearm reliever Cory Gearrin to begin the season in Atlanta.

Walden will certainly be part of the Opening Day roster if he is able to overcome the discomfort caused by a bulging disk in his back. The former Angels closer has made some recent improvement and could be cleared to throw off the bullpen mound within the next few days.

If Walden is not ready for the start of the season, the final bullpen spot could go to Anthony Varvaro, who is out of options. Varvaro improved his bid with two strikeouts in a scoreless inning against the Nationals on Monday. He impressed Gonzalez with a 3-2 curveball that froze Bryce Harper to end the sixth inning.

"That's one thing we haven't seen all spring is that big breaking ball," Gonzalez said of Varvaro, who has completed consecutive scoreless outings since allowing the Tigers five runs and seven hits in just one inning on Thursday.

Adjustments pay off for Maholm against Nats

VIERA, Fla. -- After battling inconsistent command in his two previous starts, Paul Maholm spent the past few days making some slight mechanical adjustments to his delivery. His efforts appeared to be beneficial as he baffled the Nationals for five innings during Monday's 7-2 win at Space Coast Stadium.

"That was their number one lineup," Braves manager Fredi Gonzalez said. "He had his breaking ball biting. He had a nice spin on his breaking ball and commanded the fastball to both sides [of the plate] and threw some nice changeups. He did a nice job."

Working five innings for the first time this spring, Maholm surrendered two hits, tallied five strikeouts and induced eight ground-ball outs. The only ball the Nationals hit out of the infield against him came courtesy of Bryce Harper's two-out single to right field in the first inning.

"No matter what lineup you're facing, you want to feel comfortable," Maholm said. "You want, at this point, to start getting your pitches where they need to be. Both breaking balls were working well today, and the few changeups I threw were good. To have a bunch of ground balls is pretty much what I need. That's definitely the most normal I've felt on the mound since we've been down here."

Maholm allowed five earned runs in 2 2/3 innings against the Phillies on Feb. 28 and uncharacteristically issued four walks in 3 2/3 innings against the Yankees last Tuesday. Leading up to this outing against the Nationals, the 30-year-old southpaw focused on regaining his timing by slowing his delivery.

"Whenever I get kind of off-balance, my arm is kind of behind and I have to kind of rush and get it back to where it is supposed to be," Maholm said. "I was just kind of missing pitches. That's the way it has been the last couple of outings. Hopefully, I'm smart enough to figure it out and keep it going the same way the whole time."

Braves to honor Murphy with bobblehead night

VIERA, Fla. -- The Braves will give fans a chance to honor two of the organization's most beloved figures this summer. Two weeks after inducting Chipper Jones into its Hall of Fame, the club will stage Dale Murphy Night at Turner Field. Murphy's career will be celebrated during an on-field ceremony preceding the July 11 game against the Reds. The first 20,000 fans in attendance will receive a commemorative Dale Murphy bobblehead, presented by Coca-Cola and Delta Air Lines.

While spending 15 of his 18 Major League seasons with the Braves, Murphy won consecutive National League MVP Awards (1982 and '83) and earned seven All-Star selections. The former Gold Glove Award-winning outfielder ranks second in Atlanta history (since 1966) in home runs (371), RBIs (1,143), hits (1,901), runs (1,103), and games (1,926). He was inducted into the Braves Hall of Fame in August 2000.

Worth noting

• When Jason Heyward revealed he had some soreness in his right shoulder on Monday, Gonzalez opted to not take him to Viera for the game against the Nationals. Heyward still took batting practice at Champion Stadium and is expected to be back in the lineup for Tuesday's game against the Cardinals.

• O'Flaherty will make his spring debut with a one-inning appearance against the Cardinals on Tuesday. The veteran left-handed reliever has made steady progress since being sidelined during the early days of camp with a strained left groin.

• B.J. Upton singled in his four consecutive at-bats that extended from Sunday's game against the Marlins through the second inning of Tuesday's game against Stephen Strasburg and the Nationals. Upton has batted .405 (15-for-37) with three doubles and a home run through his first 13 games of the spring season.