WOODBRIDGE, Va. -- In his first rehab start for Class A Advanced Potomac on June 6, Nationals left-hander Gio Gonzalez (shoulder inflammation) was rocked for eight earned runs on seven hits, including a grand slam, over 3 2/3 innings. The Wilmington Blue Rocks, the Class A Advanced affiliate of the Royals, attacked early-count fastballs with an aggressive approach at the plate while Gonzalez struggled with command and issued four walks.

Gonzalez learned from that experience in his second rehab start Thursday night against the White Sox Class A Advanced affiliate, Winston-Salem, at Pfitzner Stadium. He focused on throwing first-pitch curveballs for strikes and varying his pitch selection to keep hitters on their toes.

The result was a much-improved performance from Gonzalez, who has been on the 15-day disabled list since May 18. The left-hander threw 79 total pitches, 45 of them for strikes, and allowed just one earned run on two hits over four innings while striking out seven.

"It was one of these games where you needed to bounce back," Gonzalez said.

After the four free passes in his first outing, Gonzalez's command was significantly better this time around.

"When it came down to it, I wanted to work on certain pitches," Gonzalez said. "So falling behind on them wasn't an issue. It was more like I wanted to get that first-pitch curveball for a strike so I can have that peace of mind."

Similar to his first rehab start, Gonzalez made it through the first two innings unscathed. On Thursday night, he threw 33 pitches, struck out three and walked two without surrendering a hit in his opening two frames.

However, in both starts, it was the third inning where Gonzalez ran into trouble. On June 6, Gonzalez opened the third inning by giving up two singles and a walk before a grand slam brought home four runs. He then put three more runners on base after a double, a walk and a hit batter before getting out of the inning.

On Thursday, Gonzalez surrendered two walks and an RBI single in the third inning, but that was the only run the left-hander surrendered. Just like on June 6, Gonzalez said he got tired in the third inning. But instead of unraveling, he was able to fight through it and prevent significant damage.

"It's good to hear from some of these guys saying that, 'You looked even-keeled the whole time,'" Gonzalez said. "When you hear that, it means that you're making progress. You're stepping to the right direction. … I didn't change my motion, I didn't think negative, I kept battling and kept going forward."

Gonzalez showed more improvement in the fourth inning. On June 6, Gonzalez let up four more runs in the fourth inning before he was pulled. On Thursday night, though, the left-hander struck out the side, including a nasty curveball to Zach Voight for the second out that was reminiscent of Gonzalez at his best.

"I felt like I was a little more on top of the ball this time," Gonzalez said. "Fastball was coming out with more life. It just felt like right where I needed to be."

After his promising performance, Gonzalez was confident he would be returning to the big leagues for his next start. He admitted there are still small adjustments to be made moving forward, but he reported no pain or problems with his shoulder, which is the top priority.

"I'm ready to go," Gonzalez said. "I'm ready to slot myself back in there. Arm feels great, and I feel like I'm ready to go up there and do my part as a starting pitcher."