Justin Upton was walking a little gingerly when he strolled into the Braves clubhouse Sunday morning, wrap on his left leg from a foul ball off the shin earlier in the week, and nursing a muscle strain in his lower back. But he was smiling as he came in.

“A little sore,” Upton said of his back. “It’s not as bad as it was last night, so that’s a good sign.”

Upton was out of the lineup Sunday afternoon, something Braves manager Fredi Gonzalez had planned to do after Upton’s back tightened up several times during Saturday night’s game.

A five-hour flight to San Francisco might not be the best remedy for a stiff back, but Upton is hoping he’ll be ready to play again Monday night when the Braves open a three-game series against the Giants.

“That’s what I want to happen,” Upton said. “Get up, get moving around and hopefully be in there tomorrow.”

Upton felt his back spasm for the first time Saturday night after he collided with Anthony Rizzo, tagging him out during a rundown. He managed to stay in the game for two more innings, singling up the middle in his next at-bat. But when Jeff Samardzija hit him with a 94 mph fastball in the same area of his lower back in the sixth inning, Upton left the game.

“Yeah, not too good, makes you not swing as hard though,” Upton said.

As for the rundown, when the ball changed hands seven times before Upton finally got the putout after rushing in from left field?

“We’re always running in there trying to sneak an out,” Upton said.

“I’ve been waiting to get into a rundown all year long. We’re always like the last man standing and they make the out. Finally got in there.”