After Wednesday's loss, rookie outfielder Ezequiel Carrera was seen shaking hands with multiple teammates inside the Indians' clubhouse. Carrera would be the most likely player to be optioned back to Triple-A Columbus in order to clear room on the roster for Sizemore.
Sizemore, who has been on the DL since May 16, did two laps around the bases before retreating to the clubhouse. With head athletic trainer Lonnie Soloff watching, Sizemore did two sets of home to first base, first to third, and third to home with timed breaks between each burst.
"I felt good," Sizemore said. "I was running the bases with no problem. Everything went well."
The Indians have a scheduled off-day on Thursday, which is when Sizemore is eligible to be activated. The team has remained hopeful that he could return for a three-game road series this weekend against the Rays, but Soloff said earlier this week that such a move was "not a foregone conclusion."
Acta would not confirm that Sizemore would be in the lineup on Friday.
"I'm not going to give you the date," Acta said. "We haven't made the decision. We're expecting him to join us for the weekend, but the weekend stretches all the way from Friday through Sunday."
Sizemore injured his left knee during a hard slide into second base during the sixth inning of a game against Tampa Bay on May 10. His stint on the 15-day DL is retroactive to May 11.
In 18 games this season, Sizemore has hit .282 with six home runs, 10 doubles, 11 RBIs and 15 runs scored. He was limited to only 33 games last season due to an unrelated left knee injury, making his initial return to Cleveland on April 17 this year.
Sizemore said the biggest issue he faces is regaining his timing at the plate.
"I still feel good," Sizemore said, "but there's nothing I can do in the cage or out on the field in BP that's going to simulate the timing of a big league at-bat. So there's definitely going to be an adjustment period."