Jenkins, who played for the Brewers from 1998 to 2007, finished his career by winning a World Series ring as a part-time player with the Philadelphia Phillies in 2008.
Jenkins called it a "great day for me and my family to share with you guys, and obviously with the fans" during a news conference before the Brewers hosted the Pittsburgh Pirates.
The left-handed outfielder batted .275 with 221 home runs in 1,349 games over 11 seasons. His 212 homers with Milwaukee are second only to Hall of Famer Robin Yount's 251.
Jenkins' statistics were down in the final couple years of his career, and no team signed him in 2009 or this season. Despite not turning 36 until later this month, Jenkins decided it was time to call it quits and at some point join the Brewers organization in another capacity.
"It's a tough decision to make," he said. "Everyone wants to keep playing. I still want to keep playing, but at some point you have to just decide it's time to start a new chapter in your life. ... When your phone isn't ringing anymore, that's pretty much when it's time to start a new chapter."
Jenkins was a bright spot on several dismal Brewers teams that averaged only 72 wins a year during his 10 seasons and only played winning baseball in his final year, finishing 83-79.
"Going to the field every day for me was the fun part, hanging out with the guys," he said.
"Geoff was very helpful, and [former manager] Ned Yost always brought this up, with developing the younger players," Melvin said. "It's always good to have someone that plays the game that way when you are in the developmental stage with a number of players."
Melvin said he would talk to Jenkins at the end of this season about joining the organization.
"With him living in Arizona and with us in spring training in Arizona, I'm sure we can put something together," Melvin said.
Jenkins was the ninth pick in the first round of the 1995 draft and was passed up by Melvin, who was then the GM of the Texas Rangers. Melvin selected Jonathan Johnson, a right-hander from Florida State, with the seventh pick.
"I made a mistake," Melvin said. "I should have taken Geoff Jenkins because Jonathan didn't make it."
"You can cross that off your list, although I'd fit under the [salary cap]," he said.