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. Source: ESPN