DURHAM, N.C. — As September roster expansion nears, Austin Riley is heating up.

Riley homered in both games of a doubleheader Tuesday night, helping Triple-A Gwinnett split the set against Durham (Rays) at Durham Bulls Athletic Park.

Riley, the Braves' No. 3 prospect and No. 37 overall on the BA Top 100 Prospects list, upped his slash line to .273/.314/.515 in August with a pair of 1-for-3 performances. It’s a notable turnaround from July, when the 21-year-old third baseman hit .265 with zero home runs after returning from a right knee sprain that knocked him out for most of June.

“Everything is coming back in sync,” Riley said. “Knee feels good, that’s the biggest thing. Coming back was slow, just seeing that pitching everyday, but things are going good right now and I’m just trying to finish strong.”

Riley started game one off with a bang, annihilating a fastball high and outside from Chih-Wei Hu deep over the wall in right-center to stake Gwinnett to a 1-0 lead in the first. The blast landed four rows back in the stands to one of the deepest parts of the park in right-center.

That was his only hit of game one, but he had more in him in game two.

Again in the first inning, Riley went down and got an 82 mph changeup from Jacob Faria and sent a screaming liner over the high wall down the left-field line. The two-run homer was Riley’s seventh at Triple-A and 14th overall on the year, and further cemented that he is finally past his knee injury.

“He got back here and it wasn’t quite right yet, I think just now he’s starting to get healthy and get his swing back,” Gwinnett manager Damon Berryhill said. “He’s kind of getting his power swing back. It’s not to say he didn’t have it. He’s hit some balls real hard—at Norfolk he hit the ball extremely well, it was just dead into some gale winds—but tonight I think his swing just got a little more length through it and I think he’s starting to feel better.”

Riley’s recent surge naturally has led to calls for the Braves to call him up as they head into the meat of the pennant race, although they can afford to leave him in Triple-A to further develop if they choose. Johan Camargo has hit 283/.350/.463 while playing standout defense at the hot corner since taking over as Atlanta’s starting third baseman on May 19 (the day they released Jose Bautista), and Riley openly acknowledges he still has things to work on in the minors.

“I’m still having trouble with sliding my body just a little bit,” Riley said. “I’ve been really working hard on that the past couple weeks. We’re trying to work a few things out with that, and tonight I felt really good.

“Obviously the sliding of the swing, some approach stuff, the strikeouts are obviously high right now (77 in 61 Triple-A games), but I think that’s going to come with the power that’s there. We’re just trying to fine-tune to cut those numbers down as much as we can.”

Even so, Riley’s two-homer night and steady improvement are just more signs he’s moving closer and closer to Atlanta. If all goes according to plan, it won’t be long at all.

“He’s close,” Berryhill said. “In my opinion, he can play up there. Defensively, he’s been solid for us all year, and offensively he’s mature enough and has the ability to put quality at-bats together and he’s got plus power. That’s going to be up to them.”