The Pirates placed right-hander Gerrit Cole on the 15-day disabled list, retroactive to June 4, due to right shoulder fatigue.
Cole came forward after his most recent start Tuesday in San Diego to let the club know something wasn't right.
"We give Gerrit a ton of credit for making us aware it just didn't feel right, felt a little tired," general manager Neal Huntington said. "We talked about, do we just skip this start? Have him come back next time? At the end of the day we felt it was probably better to just be aggressive with it now."
Cole said he has never experienced this type of shoulder fatigue before and doesn't see it as a "huge issue."
"It's been kind of a gradual onset. I just didn't bounce back the way I anticipated after the last start," he said. "It's frustrating but at the same time hopefully we can nip this in the bud.
"I don't see it as a huge issue. It needs to be taken care of. I think this is the best way to tackle this now and deal with it, rather than maybe prolonging it and hoping for the best."
Huntington declined to be more specific with the shoulder problem, other than to repeat the word "fatigue."
"All the tests we've done so far have confirmed shoulder fatigue," Huntington said. "Gerrit feels good with it. We feel good with it. We'll see how the treatment goes. ... Fatigue is fatigue. Injuries are gray areas. He's got some fatigue in there right now."
Cole is likely to miss at least his next two starts and possibly a third, but Huntington left the door open for a longer rest period if necessary.
"If everything goes as planned he'll come right back after the DL stint. But if we need more time, we need more time," Huntington said.
Manager Clint Hurdle said there have been some signs in Cole's past several starts that point to an overload.
"There's been some indicators that have popped up that haven't been the norm if you look at indicators from last year," Hurdle said. "When a player admits it, it's usually about the third time it happens. Look at pitch per inning. Look at strike percentage. All these things, the number of pitches out of the stretch, versus number of pitches out of the windup."
Cole, 6-3 this season with a 3.64 ERA, went 52/3 innings against the Padres, allowing one run and four hits. Three of the hits came from the final three batters he faced.
Experiment a success
Top prospect Gregory Polanco seems to have responded well to batting leadoff for Class AAA Indianapolis since he was moved there a week ago.
"He's continued to swing the bat really well. He's naturally going to work a count, drive a ball gap to gap and naturally drive a few balls into the seats," Huntington said. "Every day that goes by that he continues to be successful gives us that much more comfort. Our goal is to bring him here when we feel like it's the right time. In an ideal world we'd like to get him some more plate appearances down there. What he's doing is allowing us to feel comfortable with shortening that time frame a little bit."
When he does come up -- and no, Huntington has not said when -- the club might still stick with Josh Harrison at the top of the order. Harrison has batted .330 in 25 games in the leadoff position.
"It's a great problem to have," Huntington said. "It will be an interesting discussion when we get to the point, where does he hit in the lineup? It's hard to take that spark plug out of the lineup. That would be a great thing to drop Gregory into a less demanding role. ... Gregory can come in and be a guy and not have to be the guy."
Throwing the sink
Charlie Morton was scheduled to start, but was moved back to today to gain more time to work on his signature pitch.
"Based on Charlie's last effort, just to give him a chance to refine delivery, refocus on commitment to the sinker. The sinker's got to play for him," Hurdle said.
Morton struggled with location in his past several starts, which has translated to higher pitch counts earlier in the game.
"You know it's not working, you know it's not in play when there's 100 pitches by the sixth inning," Hurdle said. "He's had to go other ways to get the outs. We know he's capable. He's finding his way back and recalibrating."
Back on the horse
Starling Marte returned to the lineup in left field after missing four consecutive starts.
Hurdle said it was as good a time as any.
"I don't think you're going to handpick a perfect day. You just need to choose a day, run him out there and go," Hurdle said. "I do want to give an opportunity for our playmakers to get back on the field. He's a playmaker. He's a difference maker. We'll see what he can make of it. I know he's itching to play."
Gaby Sanchez batted cleanup in place of Ike Davis, who Hurdle wants to give some time to work on some things.
"Ike's been challenged here the past 10 days. Hit a bomb in [Los Angeles] and the at-bats have been challenging," Hurdle said. "He was one of our hottest hitters in the month of May.
Hurdle said he anticipates using the right-handed Sanchez for the first few games of the Chicago Cubs series, as well, with a right-hander slated to pitch tonight and a left-hander Tuesday.
Jenn Menendez: email@example.com and Twitter @JennMenendez.