Less than four months after suffering what some doctors believed could be a career-threatening ankle injury, Joba Chamberlain made his first rehab appearance and could be back with the Yankees in a few weeks. The right-hander pitched one inning with the Gulf Coast League Yankees yesterday and hit 97 mph, another encouraging sign after Tommy John surgery last summer. "It's the start of the rehab process, so hopefully we get him back no later than the first week of August," general manager Brian Cashman said.