Though the Pirates' production from their starting rotation has taken a dip from last season, the organization believes the staff will improve, general manager Neal Huntington and manager Clint Hurdle said.
The rotation entered Sunday's game with a 4.50 ERA, which was tied for 24th in the major leagues.
"There's been volumes within the work that have been very clean and efficient," Hurdle said. "It's consistency, it's conviction with that intent, to get the execution that we need."
Edinson Volquez has been the exception, posting a 1.71 ERA in 21 innings of work. Gerrit Cole helped the cause Sunday with eight innings of one-run ball.
"At times we've not made the plays behind them, at times they've not made the pitches that they have in the past," Huntington said. "At times we haven't scored. We're not playing all that well right now. We'll get on the right track and get clicking on all cylinders. We really haven't clicked on all cylinders to date."
Wandy Rodriguez has experienced the most difficulty out of the gate. He had a 7.65 ERA in his first 20 innings, allowing 26 hits, 17 runs and a .306 batting average against.
"It's four starts," Huntington said. "We're seeing some good signs, we're seeing some signs that we've got to do some things to help him get a little bit better."
Rodriguez has never been a hard thrower, but he has lost some velocity. He topped out at an average of 90.2 mph in 2009 and averaged 89.3 mph last year, but he is at 88 mph through his first four starts.
"It was a little bit crisper in spring training than we've seen so far," Huntington said. "Pitchers tend to lose velocity as they age. It's not just about velocity, it's about deception, the ability to throw all three pitches for strikes."
Rodriguez has pitched effectively in the high 80s and low 90s. But when his fastball is in the 87-90 mph range, the separation in speed between that and his changeup decreases and makes both pitches less effective.
"If your changeup is 82-84 and your fastball is 88-90, you're not even getting a 10-mile separation, which is normally what you're looking for between the fastball and the changeup," Hurdle said.
Hurdle indicated that the Pirates will let Rodriguez work it out.
"When you put guys in your starting rotation, you anticipate giving them the ball every fifth day," he said.
Right-hander Jameson Taillon, the Pirates' top pitching prospect, is doing well after having Tommy John ligament replacement surgery, Huntington said.
"Early rehab is great, he's getting range of motion back, all positive so far," he said.
Taillon had the surgery April 9. He will miss the remainder of the season and will be out until at least next April.
Taking the day off
Pedro Alvarez was not in Sunday's lineup. He entered the game with a .288 on-base percentage and was 0 for his past 9, though he had reached on an error and a hit-by-pitch.
"He has hit a number of balls on the nose, hit them right at people," Huntington said. "He's just the victim of some bad luck at this point in time, but he's swung the bat well."
Bill Brink: email@example.com and on Twitter @BrinkPG.