James McDonald, a pitcher who might prove most pivotal to the Pirates' season, makes his 2013 debut today, and his manager is not entirely sure what to expect.
"It was all over the place," Clint Hurdle said of McDonald's spring-training performance. "We saw some real good stuff, and we saw some stuff that flashed back to the second half of last season."
McDonald was the Pirates' best pitcher in the first half of 2012 as his team soared to first place in the National League Central Division. In 17 starts, McDonald went 9-3 with a 2.37 ERA. In 13 appearances in the second half, 12 of them starts, McDonald went 3-5 with a 7.52 ERA.
In spring training, McDonald had a 4.19 ERA in five starts. He spent a lot of time pitching against minor leaguers at Pirate City, as did most of the team's starters who had already secured a spot in the rotation, and those statistics don't factor into his Grapefruit League line.
But McDonald's spring performance isn't necessarily foreshadowing of what is to come. In spring training 2012, McDonald had an 8.31 ERA. Once the regular season started, he was a dominant pitcher.
Part of McDonald's struggles come from the difficulty he has in repeating his delivery. In the second half, his mechanics were inconsistent and he became much more ineffective.
Hurdle was pleased with McDonald's fastball command this spring and his ability to use his curveball and changeup aggressively.
"He understands what's at stake," Hurdle said.
Hurdle said it's not a threat, but it's a reality that the Pirates have Charlie Morton and Francisco Liriano rehabilitating from injuries and less than two months away from returning to the major league roster. Additionally, the Pirates have top prospect Gerrit Cole primed for his debut as early as June.
"I have every confidence that with the lessons [McDonald has] learned, the experience he's garnered, he's going to take the ball and he's going to be aggressive," Hurdle said.
Progress for Karstens
The Pirates expect Jeff Karstens, who was expected to be the No. 4 starter before a shoulder injury in spring training, to begin throwing off flat ground by the end of the week.
"There hasn't been any planned mound work scheduled of yet," Hurdle said.
Karstens first experienced discomfort a week into spring training. After making a few starts, Karstens was scratched from an outing March 24. He has not thrown since.
April Fools' joke?
Remember that bag of rosin that exploded in A.J. Burnett's hand opening day?
Hurdle suggested it might not have been an accident that bag appeared -- and disappeared -- on April Fools' Day.
Burnett smacked the bag of rosin against his hip before taking the mound one inning Monday, and the bag fell apart in his hand, spilling rosin all over his arm and the grass behind the mound.
"It's fun when a practical joke can get played in the middle of a game with the rosin bag exploding," Hurdle said. "A strategically placed rosin bag. You never know what we're up to in here."
Then again, maybe it was just a coincidence.
"You'll never know," he said.
Injured arms update
No. 5 starter Jeff Locke threw 91 pitches over six innings in an extended spring-training game Tuesday in Bradenton, Fla. He is scheduled to make his season debut Sunday. ... Morton (Tommy John surgery) was scheduled to throw 35 pitches in a simulated game Wednesday. ... Liriano (broken right humerus) threw 20 pitches in batting practice .
Michael Sanserino: firstname.lastname@example.org, 412-263-1722 or on Twitter: @msanserino. First Published April 4, 2013 4:00 AM