Sizemore has been sidelined with a left knee injury since May 16 of last season and the Tribe's star center fielder underwent microfracture surgery on the joint last June. After a grueling and complicated rehab process, Sizemore appears healthy and ready to rejoin the club.
When Sizemore is officially added to Cleveland's roster, the likely candidate to be removed from the fold is outfielder Travis Buck, who carried a .136 average into Saturday's action. Buck has a Minor League option remaining, meaning he can be sent down without consequence.
Sizemore will immediately move to center field upon his return, meaning that Michael Brantley will shift out of center and into left. Brantley has also hit well out of Sizemore's old home in the lineup -- the leadoff spot -- batting .333 with a .400 on-base percentage through 13 games.
Acta has not revealed where Sizemore will slot into the lineup, but seems likely that the center fielder will be placed atop the order. Sizemore, who was limited to just 33 games a year ago due to the knee issue, said he is comfortable with whatever decision Acta makes.
"It's tough. The team's swinging well," Sizemore said. "You don't want to mess with that. It's up to Manny. He knows I'm good with whatever he decides. We'll figure out what's best for the team and go from there."
Entering Saturday, the Indians were in first place in the American League Central with a 9-4 record and the team's offense was averaging more than five runs per game. Acta was hardly worried that adding Sizemore -- a three-time AL All-Star -- to the mix was going to disrupt the lineup.
As well as the Tribe's offense has performed as a whole, though, it is worth pointing out that the club's production out of left field has been disappointing up to this point. Through the team's first 13 games, Indians left fielders had combined to hit just .128 with no home runs and 10 RBIs.
"Regardless of what type of lineup you have," Acta said, "when you add Grady Sizemore to any lineup, any team in America, you're adding to it. Is that an understatement?"
Due to various injuries, the 28-year-old Sizemore has not played a full season since 2008, when he hit .268 with 33 home runs, 39 doubles, 38 stolen bases and 90 RBIs over 157 contests. Last year, he hit at a .211 clip, but was hindered by his knee issues.
Sizemore has been testing his knee lately in a Minor League rehab assignment with Triple-A Columbus and Double-A Akron. Over five Minor League games, he has hit .353 (6-for-17) with one homer and four RBIs. That lone blast came in a 1-for-3 showing for Columbus on Thursday.
The rehab stint followed a slow rehab progression during Spring Training. After months of strength and flexibility training, Sizemore slowly began adding various running and agility workouts to his routine. He was back in games before the end of Spring Training, running, diving and sliding without pause.
Throughout his rehab, Sizemore kept in contact with Dr. Richard Steadman, who performed the center fielder's surgery in Vail, Colo., in June. Sizemore said on Saturday that he has not consulted any doctors in about a month -- the last time being prior to his first Spring Training game.
"It's been consistent the last month or so," Sizemore said of his knee.
That said, Sizemore understands that it will take time to get used to the everyday grind of a baseball season again.
"I'm not expecting to play seven days the first week," Sizemore said. "I'm sure it will be a slow progression. I would expect [Acta] will work around off-days and give me days between. But I don't want to have too many days off, because then [the knee] will get stiff."
The biggest obstacle remaining is regaining his timing at the plate.
"Obviously, there's going to be some adjustments with my timing," Sizemore said. "The game always speeds up, but I've been here before and I know what it takes."
That process is set to begin soon.
"We're ready," Acta said. "We're gauging how he is physically and getting him ready to possibly be activated soon."