Gerrit Cole has been efficient and composed in his first three starts, keeping things simple by locating his fastball and not trying to do a whole lot else.
He has given the Pirates what they have asked: He has walked just one batter, attacked the strike zone and won all three games he has pitched. But with the impending returns of A.J. Burnett and Wandy Rodriguez in the next few weeks, there is speculation Cole may be sent down, because he is the only player in the rotation with a Minor League option besides Jeff Locke, who has a 2.06 ERA and has not lost since April 7.
"I try to stay detached from all that, but it's not easy," Cole said. "It's not nice hearing about that kind of stuff. So, as much as I can, I try to stay detached."
Cole, the No. 1 overall pick in the 2011 Draft and the club's top prospect, will take the mound at home Friday against the Brewers, who will also send a rookie to the mound.
Johnny Hellweg, a 6-foot-9 righty, will make his Major League debut, getting the ball after Alfredo Figaro went on the disabled list. Hellweg was 7-4 with a 2.82 ERA for Triple-A Nashville, and the 24-year-old is the club's No. 3 prospect, according to MLB.com.
"The looks we got in Spring Training was he works quick," said manager Ron Roenicke. "Good stuff with the curveball and the fastball down in the zone, good movement on the fastball. He's got velocity on it. But he was throwing strikes in Spring Training. I know looking at his numbers and following him through the year this year, walked a lot of people early, and then settled down and is really throwing the ball well."
Hellweg learned of his promotion after the team returned to Nashville from a four-game series in New Orleans. His coaches told him the news in front of the whole team.
"I guess that was a feeling I've never had," Hellweg said. "It was kind of surreal. I guess the closest I've ever been to floating."
Pirates: Bats slowed by Felix, but not stopped
The Pirates had at least 10 hits in six straight games entering Wednesday, but Felix Hernandez did not let that bother him. He allowed two runs and six hits over seven innings and fanned 11.
The Pirates' offense, which had scored 30 runs over its last four games, was slowed, but did enough to beat the Mariners, 4-2, with two runs in the ninth. Entering Wednesday, the Pirates were tied for 19th in baseball in runs scored, when they had been in the bottom third of the National League in that category for most of May.
Brewers: Rotation depth is concern as Estrada suffers setback
Hellweg got the call-up because the Brewers' rotation has been so damaged this season.
Marco Estrada, whom Milwaukee hoped would be back soon, had his rehab frozen and will throw bullpen sessions until his hamstring is 100 percent. He has been on the disabled list since June 5 with tightness in his hamstring and he felt it tighten in the third inning of his rehab start with Class A Wisconsin on Sunday.
Roenicke is hoping some of the young, untested starters, such as Hellweg and Donovan Hand, can fill the void.
"We've got a lot of guys that are kind of in the same boat and trying to figure out where everybody belongs," Roenicke said. "Hopefully somebody pitches so well that we can't take them out of the rotation. That's what I'm hoping."
• Roenicke said Thursday that the goal is for outfielder Carlos Gomez to return to the starting lineup on Friday. Gomez strained his left shoulder Sunday and hit in the batting cage Thursday, a day after he took dry swings.
• The Pirates are 8-0 this season after scheduled off-days.
• Pittsburgh is 6-4 against the Brewers this season, with three of those losses in Milwaukee, where the Bucs are 9-24 since 2010.
• Starting Friday, 12 of the Pirates' next 15 games are at home, while the Brewers begin a seven-game road trip.
Steven Petrella is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.