LAKE BUENA VISTA, Fla. — The Upton brothers reported to Braves spring training Sunday, which meant it was time for the curious to view B.J. Upton's swing and see whether he'd made significant changes since a career-worst 2013 season.

It didn’t take long to see that yes, he has. The center fielder has junked a lot of the moving parts he had in last year’s swing, including a foot-tap timing mechanism, pronounced front leg lift, and excessive head and bat movement.

“He’s a lot more efficient,” said Braves hitting coach Greg Walker.

Walker watched Upton swing Sunday against a coach pitching from the mound, after watching him use the same streamlined swing to hit balls flipped to him in the batting cage a few weeks ago when Walker visited him in Tampa to check up on his offseason progress.

In the first season of his five-year, $75.25 million free-agent contract with the Braves, the 29-year-old hit .184 – more than 70 points below his previous career average – with just nine homers and 12 stolen bases in 126 games. Upton had a .268 OBP and a .289 slugging percentage that was 133 points below his previous career average.

Manager Fredi Gonzalez said the Braves’ message to Upton and Dan Uggla, who also had a career-worst season, was that 2013 is over and it’s time to start with a clean slate.