OAKLAND, Calif. -- Bob Melvin and Chili Davis have remained close friends since their days as teammates with the San Francisco Giants as young major leaguers.

Twice before, Melvin had expressed interest in hiring Davis as his hitting coach -- in Seattle and again with the Arizona Diamondbacks. They have golfed together and gone mountain biking.

Davis is on Melvin's staff at last, hired Saturday as Oakland's hitting coach to complete the Athletics' staff heading into 2012.

"I do understand this is a business. Bobby and I have been friends for a very long time," Davis said from his home in the Phoenix area. "I feel very comfortable having him as the guy that's running the show on the field for us. It's good to know you're working for someone you're familiar with, who's a friend and he has your back and you have his back also."

Melvin took over for the fired Bob Geren in June and went 35-35 after the All-Star break and 47-52 overall while dealing with key injuries to the starting rotation. He received a three-year deal late in the season to continue as the club's manager. The A's (74-88) went a fifth straight year without a winning record or playoff berth since being swept in the 2006 AL championship series by Detroit.

Davis plans to get to work right away making contact with players, meeting in person with those who are already in Arizona.

Oakland has a pair of switch-hitting starters, Jemile Weeks and Cliff Pennington, who stand to learn plenty from Davis.

"The biggest thing I've learned the last two years is the most important thing they look for is that you really care and you're going to be consistent with what you say to them and that you really are paying attention," Davis said.

Davis spent the first seven of his 19 major league seasons with the Giants, who selected the Jamaica native in the 11th round of the 1977 draft. Returning to the Bay Area to work under Melvin was appealing.

"I know he's tried to hire me twice, once with the Seattle Mariners -- a job I was looking forward to getting and didn't get it -- and then with the Arizona Diamondbacks. I guess the third time's the charm," Davis said. "This couldn't have happened at a better place and a better area. I have ties there. I have always loved the Bay Area. I spent a lot of time in the Bay Area. I started my career there. That's a huge part of the excitement for me."

Davis, one of baseball's most accomplished switch-hitters, was a three-time All-Star and won three World Series titles while also playing for the Angels, Twins, Royals and New York Yankees.

He is a career .274 hitter with 350 home runs, 1,372 RBIs and a .451 slugging percentage in 2,436 games.

Davis replaces Gerald Perry, whose contract wasn't renewed.