CHICAGO -- Bradley Zimmer was optioned to Triple-A Columbus last week to refocus on his offense, but now he faces a different kind of setback.
Zimmer hurt his right shoulder doing hitting drills at Columbus on Monday, Indians manager Terry Francona said before Wednesday's game against the White Sox. Zimmer will rest for five days and will tentatively plan to resume baseball activities over the weekend.
"He was doing a drill, like a one arm drill and he aggravated his shoulder," Francona said. "I was texting with him yesterday. He's not worried about it, he just aggravated it doing it. It's the lead shoulder, so he'll be fine. He just has gotta go five days without doing anything."
The Indians' first-round Draft pick in 2014, Zimmer had struggled in 34 games with the Major League club this season. He hit .226/.281/.330 with only seven extra-base hits, and he struck out 44 times in 106 at-bats.
Zimmer also dealt with a rib bruise for a couple of weeks at the end of May. He was activated from the disabled list on June 1 before being optioned June 5 to make room for Lonnie Chisenhall.
Complicating the Indians' outfield shuffle will be the activation of Brandon Guyer off the disabled list before Thursday's finale in Chicago, "as long as he gets through [batting practice] OK," Francona said. The Indians are having trouble deciding on a corresponding roster move, the manager added.
When asked who the Indians would send down, Francona responded, "There's not one that just is sitting there and you go, 'Yeah, I agree.'"
Miller throws bullpen session
Andrew Miller continued to work his way back from right knee inflammation, throwing another bullpen session before Wednesday's game.
Miller has been sidelined since May 26 with this injury, and he spent time on the disabled list earlier this season with a strained left hamstring. Francona said Miller's next step is to face hitters in live batting practice or simulated innings.
"He did well, he did real well, probably his best one yet," Francona said. "When we get back home, we'll see if he's ready to face hitters.
"How he's bouncing back is still the biggest challenge, but he's building up, he's doing a good job, so we're making progress, which is good. I'd much rather have that happen than the other way."
Miller has now thrown three bullpen sessions in the last six days -- one in Detroit last Friday and one in Chicago on Monday. That Miller is able to rehab both his knee and any potential lingering tightness in his hamstring is a bonus, Francona said.
The left-hander is 1-3 with a 4.40 ERA in 14 1/3 innings this season, having walked 10 and struck out 23 hitters.
Indians sign 20 Draft picks
During Wednesday's 3-2 loss to the White Sox, the Indians announced the signing of 20 of their 42 Draft picks.
Second-round pick Nick Sandlin, a right-handed pitcher from the University of Southern Mississippi drafted 67th overall, was the highest selection signed Wednesday. The slot value for the pick was $939,700.
The Indians inked six of their top 10 picks, but their top three selections -- first-round pick Noah Naylor (29th overall), first-round compensation pick Ethan Hankins (35th) and competitive balance pick Lenny Torres (41st) -- remain unsigned.
Cleveland signed its picks from Rounds 2-4, 6, 8, 10, 12, 15, 17, 18, 20-22, 24, 25, 27-29, 31 and 33.
Perez stuns with quick recovery
Catcher Roberto Perez impressed Francona with how quickly he recovered from being hit in the hand with a pitch Sunday.
The Indians were worried Perez might have had to spend time on the disabled list, as they recalled top prospect Francisco Mejia for a couple of days, but Perez was healthy enough to start Wednesday to catch Trevor Bauer.

"When I went out there to check on him, by the time he got to first that thing had turned purple," Francona said. "You hate to be negative, but it sure looked like, and even the trainer was like, 'There's a decent chance there's a break there.' So not only is it not broken, but he bounces back where he can play."