Financial details of the one-year deal were not disclosed.
Hours after leaving the Astros, Hernandez was already in the Braves' clubhouse, talking to his new teammates and getting prepared for his new role in the bullpen.
"It's very nice to come to a team that has a chance to make the playoffs and go to the World Series," Hernandez said. "I've got a lot of history with the Braves."
Hernandez's arrival will not affect Randall Delgado or Julio Teheran, both of whom are competing to begin the season as Atlanta's fifth starter. The veteran hurler signed with the understanding that he will only be used as a starting pitcher when injury or a schedule change affects the rotation.
"We made it clear to Livan [that] he is not in competition for the fifth starter's spot at this point," Wren said.
The signing of Hernandez gives the Braves the flexibility to use Cristhian Martinez in a middle relief role instead of simply reserving him to work multiple innings as a long reliever. The ability to use both Martinez and Kris Medlen in one- or two-inning roles could help lessen the strain placed on primary setup men Jonny Venters and Eric O'Flaherty.
The decision to sign Hernandez came after Cory Gearrin struggled in consecutive appearances and gave the Braves reason to worry about starting the year with him in the bullpen. Hernandez and Yohan Flande will likely fill the final two available bullpen spots.
"It gives us some flexibility with guys that can do a variety of things," Wren said. "You're looking to add winning pieces, pieces that you envision using when the game is still in play. I think we've done that with Livan.
"He's got a very resilient arm. He's always been able to bounce back. He's always been able to pitch a lot of innings. He's a great competitor. He holds runners and fields his position. He handles the bat. He does so many things well that we felt he was an ideal fit."
Many Braves fans will best remember Hernandez as the 22-year-old Marlins pitcher who used plate umpire Eric Gregg's wide strike zone to his advantage while recording 15 strikeouts in a complete-game win over Atlanta in Game 5 of the 1997 National League Championship Series.
Fifteen years and approximately 3,000 Major League innings later, Hernandez finds himself thanking the Braves for the opportunity to prove he can still be an asset.
The Braves had been interested in signing Hernandez over the winter and giving him the same long relief/spot starter role that they now have, but he opted for the opportunity to be a starter with the Astros.
Hernandez went 1-2 with a 5.63 ERA while completing 16 innings in Grapefruit League action this year. His release saved the Astros $100,000, as free agents who signed a Minor League deal receive a $100,000 retention bonus if they are not placed on the Opening Day roster or released five days prior to Opening Day.
"I can't complain," he said. "I'll come over here and try to do my job."
Hernandez went 8-13 with a 4.47 ERA in 29 starts with the Nationals last year. For his career, he is 174-176 with a 4.39 ERA in 475 appearances. The lone relief appearance of his career came on Sept. 24, 1996, when he tossed three scoreless innings against the Braves.
Wren was part of the front-office group that lured Hernandez to the Marlins after he'd defected from Cuba in 1996. He remembers courting the right-hander in the Dominican Republic and showing him some of the top restaurants in the Miami and South Beach area.
This time, Wren simply had to pick up the phone and offer Hernandez a chance to prove he can still pitch at the Major League level.
"He was excited," Wren said. "There was no hesitation."
Mark Bowman is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.