He allowed two runs and two hits, both solo homers, in three innings of work against the Pawtucket Red Sox.
Kluber threw 41 pitches [24 strikes]. His fastball topped out at 90 mph, which is a good sign, considering he hasn't thrown in a real game in over three months.
“I started to feel better as it went on," Kluber said. "Once I kinda got more comfortable out there, things started to feel a little better.”
Kluber admitted he wasn't as aggressive as he needed to be to start the game. He settled in and retired the last five batters he faced.
The two-time Cy Young Award winner suffered a broken right forearm against Miami on May 1.
Kluber faced 12 batters on the day. He issued one walk and struck out two.
The Indians are hopeful he can return to the big leagues by the end of August. Kluber will make his second rehab start on Tuesday for Double-A Akron. He's expected to throw between 60-65 pitches.
"I can see the light at the end of the tunnel," he said. "It’s fun to get out there and just compete regardless of whether it’s a rehab start or a real game, so hopefully I can continue to fine tune things.”