"That might be his last time throwing before pitching for us," pitching coach Mickey Callaway said of the upcoming sim game. "We do a lot of things in September."
Callaway was referring to the fact that baseball's rosters expand to 40 players on Sept. 1, when Cleveland can add some pitching reinforcements. The Minor League season will be over soon, robbing Kluber the chance to build up his innings with rehab starts, but the pitcher could log a shorter start and have the bullpen (or possibly another starter) help pick him up.
Callaway noted that one option could be to have Kluber piggyback with a starter such as Danny Salazar or Scott Kazmir, who have each dealt with workload limits this month. Manager Terry Francona agreed that the team could find a way to make Kluber's return work, even if he is not ready to handle four or five innings right away.
"Kluber did really well today [in the bullpen], which was not a surprise," Francona said. "He's kind of flying through this. ... We'll run into September and, as long as he's throwing the ball well, even if he's not fully stretched out, he can still help us. Those are things we have to figure out."
It was initially forecasted that Kluber would be sidelined until mid- to late-September.
Kluber, who has gone 7-5 with a 3.54 ERA through 21 games this season, has yet to throw his curveball, but he will test that pitch in a flat-ground throwing session prior to possibly trying it off the mound on Saturday. The right-hander said he has been pleased with his command in his mound workouts to this point.
"Both today and Monday, I was kind of surprised how well it went," Kluber said on Wednesday. "I hadn't been off the mound in three weeks before Monday. I was expecting to be a little more erratic than it was, but I was pleasantly surprised."
Kluber said he was extremely eager to rejoin the Indians.
"Definitely. Sitting around watching is no fun," he said. "Not being able to get out there, you live and die a little more with each game, because you can't do anything about it. Hopefully soon I'll be able to get back out there and try to help out."
Jordan Bastian is a reporter for MLB.com. Read his blog, Major League Bastian, and follow him on Twitter @MLBastian. This story was not subject to the approval of Major League Baseball or its clubs.