Manager Matt Williams said Friday that, barring a setback, the left-hander will come off the disabled list early next week.
Gonzalez has been on the DL since May 18 because of inflammation in his pitching shoulder.
"I know I'm ready," Gonzalez said Thursday. "I'm ready to go. I'm ready to slot myself back in there. Arm feels great. I feel like I'm ready to go up there and do my part as a starting pitcher."
The 28-year-old allowed eight runs in his first rehab start for Class A Potomac, but improved Thursday, allowing one run on two hits and striking out seven.
"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."
He's eligible to come off the DL and pitch Tuesday against Houston, but because of an off-day Monday, the Washington Post reports that he'd be more likely to start Wednesday on six days rest.
Gonzalez, who has a 4.62 ERA this season, went 32-16 during his first two seasons with the Nationals after a trade with the Oakland A's. He made at least 32 starts in each of his previous four seasons.
The Associated Press contributed to this report.