McCann, who suffered the injury during a collision at the plate with Eric Byrnes, was walking on his own power with the help of an air cast on Sunday morning.
As he got dressed after the game, he was putting even more weight on his left leg. But he knows the next few days will give him a better indication.
"It's just going to be a day-to-day thing," said McCann, whose .350 batting average leads the National League. "But I feel 100 percent better than I did."
Immediately after the collision with Byrnes, it appeared McCann had possibly suffered a season-ending injury. His leg went numb and Braves manager Bobby Cox admits he thought his 22-year-old catcher had suffered a fracture or had badly injured his knee.
After X-rays showed no fracture and it was diagnosed as an ankle sprain, the Braves became optimistic that he might miss just a few days.
"If I can squat, I'm not going to have a problem," McCann said. "Right now, I can't do too much. I don't have any mobility."
McCann kept ice on his ankle while sleeping. But when he awoke at approximately 4 a.m. ET, he was very stiff and couldn't put any pressure on the leg. After informing the team's head athletic trainer Jeff Porter, he began to get some more feeling in his leg.
"I'm going to do whatever I have to do not to go on the disabled list," McCann said. "I've never had an injury to my ankle, so I don't know what to think."
Knowing McCann won't be available for at least a couple days, the Braves opted to promote Brayan Pena from Triple-A Richmond. Pena will share the catching duties with Todd Pratt, whose troublesome left ankle prevents him from being behind the plate every day.
To make room on the 25-man roster for Pena, the Braves were forced to designate Travis Smith for assignment. After watching Smith perform well in his spot start on Saturday night, Cox was hoping to keep the 33-year-old right-hander around for at least another week to help solidify his bullpen.
But with the uncertainty surrounding McCann, this was the only move the Braves could make.
Switching around: Considering the fact that Pena is known much more for his offensive skills, the .226 batting average he's compiled at Richmond this year is somewhat alarming. But in fairness, it's a product of his decision to end his days as a switch-hitter for about five weeks.
Wanting to generate some more power, Pena thought it would be better to simply hit from his natural right side. He decided this during the first week of the season, and then two weeks ago, he began switch-hitting again.
He's hitting .355 (11-for-31) against left-handed pitchers and .179 (15-for-84) against right-handers. Given that he began switch-hitting in 2000, it was very odd for him to see the delivery of a right-hander while batting from the right side.
"It didn't work out too good," said Pena, who got word of his promotion while he was in Norfolk, Va., at about 2 a.m. ET on Sunday. He arrived in Phoenix well before Sunday afternoon's game.
Happy birthday, Bobby: Cox celebrated his 65th birthday on Sunday, and there was reason for him to be optimistic heading into the series finale against the Diamondbacks. Since 1991, the Braves have gone 10-4 on his birthday. Kent Mercker, Greg Maddux and Tom Glavine each recorded two of those 10 victories.
This date in Braves history: It was exactly one year ago Sunday that Kyle Davies tossed five scoreless innings in his Major League debut against the Red Sox at Fenway Park.
On May 21, 1966, Hank Aaron hit the first Atlanta Braves pinch-hit homer.
Coming up: The Braves will begin a three-game series against the Padres at PETCO Park on Monday at 10:05 p.m. ET. John Smoltz (3-2, 3.47 ERA) will oppose Jake Peavy (3-4, 3.77 ERA) in the opener.