After watching them in three days of full-squad workouts, Braves hitting coach Greg Walker is encouraged with offseason adjustments made by B.J. Upton and Dan Uggla, the duo that was anything but dynamic in 2013.

Walker is not, however, jumping to conclusions.

“B.J. and Danny definitely worked smart this winter, and right now we’re on the driving range,” Walker said, using a golf analogy to describe what’s ahead. “We’re taking (batting practice), we’re in the cage flipping (balls to hitters), and our driving range right now is really good. But when the games start, we’ll be on the first tee box.

“Can they take it from the driving range to the tee box? If they do the same thing in the game that they’re doing in the work, they’ll be good. And we need them, man. It’s no secret.”

The Braves won 96 games and a division title despite career-worst seasons from both Uggla, who hit .179 with a .309 on-base percentage, .362 slugging percentage and 22 home runs, and Upton (.184/.268/.289 with nine homers). They had the two lowest batting averages in the major leagues among players with at least 300 plate appearances.

“If we want to be an elite offensive team, we have to have a deep lineup,” Walker said.

Upton, 29, reduced movement in his swing and stance, including the leg lift and long slide step with his front foot. He’s closer to how he swung early in his career with Tampa Bay.

“If you go back and watch (video of) B.J., his misses got bigger from year to year,” Walker said. “His swing got looser and looser. The only thing we told him to do — we don’t want you to change anything, we don’t want to turn you into somebody you’ve never been. All we want you to do is go back to the way you hit when you were a kid.

“And the talent is still there. If he does it right, the talent is elite. And that’s all we’ve asked him to do.”

Second lefty reliever? With Jonny Venters recovering from a second Tommy John elbow surgery and not expected back until May or June, the Braves will begin the season with Luis Avilan as their only lefty reliever, or they could add one from a pool that features rookie Ryan Buchter, non-roster invitee Atahualpa Severino, and Alex Wood, if he's not in the starting rotation.

The Braves added Buchter to the 40-man roster after an impressive season at Triple-A Gwinnett, where he had a 2.76 ERA with 103 strikeouts in 62 innings, albeit with 51 walks.

Severino made six appearances for Washington in 2011, and last season in Triple-A he had 58 strikeouts, 19 walks and a 3.60 ERA in 55 innings for Pirates and Royals affiliates.

Manager Fredi Gonzalez said going with one lefty is an option because right-hander Jordan Walden has been so effective against lefty hitters. He’s limited 349 left-handers to a .198 average and .283 OBP in his career, compared with a .244 average and .316 OBP by 334 right-handed batters.