The team confirmed Friday night that the 2015 American League Cy Young Award winner had agreed to a one-year contract. He's scheduled to pitch Saturday for Triple-A Gwinnett.
During a conference call, Keuchel said he has been pitching seven innings in simulated games in Southern California, and he's eager to start pitching for the Braves.
"I'm built up to go five or six innings at least," he said. "There's no concrete timetable, but I would expect, knowing how I operate, it wouldn't be long at all."
The veteran starter will earn $13 million this season, which is prorated from a figure of $21.21 million, sources said, confirming a Yahoo! report.
Keuchel went 12-11 with a 3.74 ERA in 34 starts last season for Houston and turned down a $17.9 million qualifying offer in November.
The two-time All-Star didn't voice any regrets about how things turned out. He joins a Braves team that won the National League East last year and is in the thick of the division race this season.
"They were one of the teams I had pinpointed going into free agency, with how youthful and exciting their team could be," Keuchel said. "I've always been an advocate of this formula -- a great mixture of veteran leadership and young talent. It could become special. Hopefully I can bring a little something extra."
Keuchel is 31. Atlanta's all-28-and-under rotation thus far has been led by 21-year-old rookie right-hander Mike Soroka, who improved to 7-1 with a 1.38 ERA by beating the Miami Marlins on Friday night.
Afterward, Soroka grinned when asked about the acquisition of Keuchel.
"It's a little surreal," Soroka said. "It's exciting when you see a team where we've got so much talent and experience. To add a guy like him hopefully gives us confidence to make a run for it."
Keuchel is 76-63 with a 3.66 ERA in seven major league seasons, all with the Astros.
"He makes everybody better," Braves general manager Alex Anthopoulos said. "The innings, the competitiveness, the experience, the winning -- there are not a lot of opportunities to get guys like this. We're real excited."
Information from The Associated Press was used in this report.