Celtics coach Doc Rivers said Kevin Garnett began working out on Monday and expects him to be out another 10 days as he rehabs and strengthens his sore right knee.Rivers had indicated around New Year's Day that Garnett would be ready by the second week in January before revising his timetable a few days later after Garnett was unable to train with the injury. "I'm hoping in the next 10 days, that area," Rivers said. "Now, I actually am pretty sure it is in the next 10 days or so. He got to start working out today for the first time." For more, visit the Green Street  blog.