© 2014 MLB Advanced Media, L.P. All rights reserved.

8/6/2014 8:50 P.M. ET

No timetable announced for Simmons' ankle sprain

SEATTLE -- Donning a soft cast and tape around his left ankle, Braves shortstop Andrelton Simmons gingerly limped around the Safeco Field visitors' clubhouse Wednesday morning. Crutches leaned against his locker.

Simmons was forced to exit in the fourth inning of Tuesday's 4-2 loss on an odd play that began when Mariners first baseman Logan Morrison grounded an RBI single into left field. As Justin Upton's throw sailed high over home plate, Simmons looped around the infield and caught his foot covering third base, then crumpled to the ground. After being examined by a trainer and manager Fredi Gonzalez, he was replaced by Ramiro Pena.

Shortly after, the club announced that Simmons sprained his ankle.

"I was really mad I had to come out of the game," Simmons said. "You have no idea. I wish it was a play where I was running and sliding -- something productive."

Simmons maintained that the ankle was feeling better Wednesday than it did the night before, but he added he had no idea if the sprain might require a stint on the disabled list. He is considered day to day.

"I'm just going to get treatment, see how it develops, see how it keeps feeling," Simmons said. "As soon as I can run a little bit, I'll be ready to go."

The 24-year-old Curacao native posted a .249/.297/.340 slash line in 107 games this season. Before the injury, he was 7-for-43 (.163) over the last 14 games.

The Braves have an off-day Thursday before they begin a critical 10-game homestand against three teams -- the Nationals, Dodgers and Athletics -- that are currently in first place in their division.

Simmons was out of the lineup Wednesday, as the Braves, who had lost seven straight entering the finale, wrapped up a two-game series with the Mariners. He remained hopeful that he could return sooner rather than later.

"It's definitely better," Simmons said. "I can walk a little with less pain, and that's progress for me."

Heyward on a hot streak after back injury

SEATTLE -- Braves right fielder Jason Heyward doesn't appear to be suffering from any rust after missing four games last week with a strained back.

Heyward went 2-for-4 on Wednesday afternoon to raise his batting average to .271, and he is 9-for-15 with two doubles, a triple and an RBI in four games since returning to the lineup Saturday.

Heyward also has recorded at least two hits in 12 of his last 20 games, a span in which he's batted .411.

"It's the second half of the season. I've had plenty of AB's now to feel out where I need to be," Heyward said on Tuesday. "I did pay attention to the games and tried to stay focused."

Heyward said he's continued to undergo treatment, but he no longer feels any pain or stiffness in his back. He unsuccessfully lobbied manager Fredi Gonzalez to put him in the lineup the series for last week's finale against the Dodgers.

"It was frustrating in L.A. trying to get back on the field," Heyward said. "I tried to convince [Gonzalez] that I wanted to play the last day there, and he said, 'No, you need to rest.'"

Worth noting

Emilio Bonifacio, acquired last week in a trade from the Cubs, batted leadoff and played center field for the Braves on Tuesday. It was his first start for Atlanta in either role and he seized the opportunity, going 1-for-4 with a stolen base while making a few impressive running catches in Safeco Field's spacious outfield.

Bonifacio was again in the leadoff spot and moved to left field Wednesday, while B.J. Upton, who entered just 3-for-27 on the road trip, returned to center after getting Tuesday night off against Felix Hernandez.

• Rehabbing reliever Jonny Venters threw 20 fastballs in a bullpen session Tuesday and felt good afterward, according to the Atlanta Journal-Constitution. Venters, who hasn't pitched in the big leagues since 2012, is trying to make his way back from a second Tommy John surgery. There is no current timetable for his return.

Adam Lewis is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.