Kluber underwent imaging texts Thursday, which showed that his ulna is mending properly. Cleveland manager Terry Francona said Kluber can begin range of motion and that he will be re-examined in two weeks.
The right-hander broke his arm when he was struck flush by a line drive by Miami's Brian Anderson on May 1. At the time, the Indians said surgery wasn't needed, and Francona said the medical staff told him Kluber was having "expected healing."
Kluber has been fitted with a protective brace. He said it was a relief to have the cast off and is excited that he "can do a lot more now."
The 33-year-old ran sprints in the outfield before the series opener against Tampa Bay.
Kluber won 20 games last season and at least 18 in each of the past three seasons. He is 2/3 with a 5.80 ERA in seven starts this year.