The two-time Cy Young Award winner is on the 60-day injured list. He is scheduled to throw 20 fastballs at Progressive Field before Cleveland's game against the Detroit Tigers.
Cleveland manager Terry Francona called the session "a big step, a good step," but cautioned that Kluber is still weeks away from potentially beginning a minor league rehabilitation assignment.
Kluber was struck on the forearm by a line drive off the bat of Miami's Brian Anderson at Marlins Park, breaking his right ulna. The 33-year-old spent several weeks in a hard cast and has continued to run and work on his conditioning while sidelined.
In seven starts this season, Kluber has a 2-3 record with a 5.80 ERA. He won the American League Cy Young Award in 2014 and 2017 and finished third in the voting in 2016 and 2018.