The Rangers slugger missed the last two games while getting treatment for an injury that he says was likely aggravated when he had a game-winning double as a pinch-hitter Sunday against Boston.
The team said after Wednesday night's 9-2 loss to the Chicago White Sox that an MRI revealed the strain.
Hamilton returned to Texas in a trade after two disappointing seasons with the Los Angeles Angels. He was an All-Star all five seasons with the Rangers before signing a five-year, $125 million contract with the Angels in 2013.
The 34-year-old Hamilton said he felt nagging groin and hamstring issues while on minor league rehab assignments before returning to the majors.