ST. PETERSBURG, Fla. -- The Tampa Bay Rays have reinstated reliever Jesse Crain from the 60-day disabled list.

Tampa Bay acquired Crain from the Chicago White Sox on July 29. The right-hander had gone 2-3 with a 1.15 ERA in 38 appearances before being placed on the DL on July 3 because of a right shoulder strain.

The Rays designated right-hander J.D. Martin for assignment before Monday's game against Baltimore.

The Rays say the results of an MRI exam Sunday showed that center fielder Desmond Jennings has a mild left hamstring strain. Jennings, injured running the bases Sunday, is listed as day to day.