CLEARWATER, Fla. -- Braves top prospect Ronald Acuna Jr., has been the Grapefruit League's biggest star thus far. By now, nothing can be considered surprising. The adjectives and superlatives are running thin.
Still, when Acuna is at his dazzling finest, it's a show that no one wants to miss.
Acuna smashed a towering first-inning home run -- and came within inches of adding another homer in the third -- at Spectrum Field on Saturday afternoon, when the Braves' split-squad fell, 10-6, to the Phillies. Atlanta lost its other game to the Cardinals, 3-0.
"He's fairly amazing,'' said Braves bench coach Walt Weiss, who ran the split-squad team in Clearwater.
Fairly?
By now, perhaps it should be resoundingly amazing.
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Acuna is batting a Grapefruit League-leading .410. In 15 spring games, he has four homers and 10 RBIs. He's slugging .744 (with 29 total bases). He has an on-base percentage of .511 and is 4-for-4 in stolen-base attempts.
And his OPS is 1.255.
Opening Day, anyone?
The Braves won't commit to that. Despite the staggering numbers, it could be that Acuna, a native of Venezuela, begins this season in Triple-A, so his service time can be preserved.
Whenever he gets the big league callup, though, one thing seems obvious.
He already has arrived.
"He's a dynamic player on both sides of the ball,'' Weiss said. "Impressive to say the least. He plays with confidence, especially for a kid his age [20]. He looks like he has done this before.
"He has the ability, the tools, the mentality to be really, really good in this game. I haven't seen anything that would tell me otherwise.''
Acuna hit his two-run homer off Phillies starter Zach Eflin. It was lifted high to left field, and Rhys Hoskins appeared to be tracking it. But it kept soaring … and soaring … and soaring … until it caromed off the back wall of Spectrum Field's left-field bullpen.
In the third, Acuna nearly got a second homer. But his deep drive was pulled back by Aaron Altherr's perfectly timed leap in center field. Acuna, before reaching second base, looked out at Altherr and tipped his batting helmet in tribute.

In the fifth, Acuna went down on a called strike three. In response, he whipped the bat through the hitting zone in frustration. No wonder. Not many things have gone wrong this spring for Acuna.
"He's special,'' Braves outfielder Preston Tucker said. "He's a five-tool player for sure. To have that kind of plate discipline and approach at age 20 … I don't see a whole lot lacking. He has the potential to make a big impact in the big leagues this year.''
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Sims still battling
Right-hander Lucas Sims, a first-round Draft pick in 2012 who's contending for a spot in the starting rotation or bullpen, allowed four earned runs and five hits over three-plus innings in his first start this spring.
He surrendered a leadoff homer to Phillies first baseman Carlos Santana, but soon settled into a nice rhythm, retiring seven of nine batters at one point. But he was lifted in the fourth after Cameron Rupp singled and Pedro Florimon was hit by a pitch.
Braves reliever Anyelo Gomez gave up three consecutive doubles, and Sims was on the hook for two more runs.
"I would've liked to have made it through the fourth, but we're on a pitch count and it's the spring,'' said Sims, who has a 7.84 ERA in five spring appearances. "I still feel real confident going into the season. If I continue to put consistent work in, good things are going to happen.''

What's ahead for Sims?
"Getting outs, putting up zeros,'' he said.
He wouldn't speculate on a potential role for 2018.
"Everybody who started before has goals and aspirations to be the staff ace,'' Sims said. "To me, that's not out of the question. I still believe I can do that. But at this point, it's wherever they need me, whatever I need to do.''
Tucker opening eyes
Tucker, acquired during the offseason in a deal with the Astros, looks like a good bet to figure into the left-field picture. Tucker was with the Astros' organization for six seasons, including two in the big leagues. Despite 24 homers last season in Triple-A, he wasn't called up and could only watch as the Astros won the World Series.
Now he's looking forward to a new beginning.
"I thought it was time for a change,'' said Tucker, 27, who was 1-for-2 on Saturday, raising his spring batting average to .378. "With the Astros, I found myself on the outside looking in. As long as I have the opportunity to play in the big leagues, that's all I'm worried about.''
Weiss said Tucker, a former All-American at the University of Florida, is a proven offensive commodity.

"His bat is his ticket,'' Weiss said. "He swings the bat. When you swing like that, there's always a chance you can make an impact at the Major League level.
"I think he has done a nice job in his first year over here. He has made an impression. He has shown some power and the ability to hit the ball from line to line. He knows what he's doing once he steps into the box.''