Hamilton, who recently underwent surgery to repair the AC joint in his right shoulder, will rehab in Houston until an unspecified time, Jeff Fletcher of the Orange County Register reports.Hamilton had surgery in early February, with an expected recovery timetable of six-to-eight weeks. That leaves him highly questionable to be ready for Opening Day, and it probably isn't a great sign that he's expected to stay in Houston for a while. The candidates to benefit from extra at-bats in Hamilton's absence include Matt Joyce, Colin Cowgill and Efren Navarro.