Having dealt with shoulder injuries the past two seasons, Jeff Karstens said he was relieved when he recently got a "more specific diagnosis" for his ailment.
Karstens visited orthopedic surgeon and Los Angeles Dodgers team physician Dr. Neal ElAttrache in California, seeking another opinion for a right shoulder injury that put him on the disabled list before the season began.
Karstens declined to share what that diagnosis was.
"I know what I have now," Karstens said.
Officially, the Pirates say Karstens' injury is right shoulder inflammation.
Karstens threw a 30-pitch bullpen session Thursday, just the second time he has thrown off a mound since shutting down activity March 24. He used all his pitches but said he is unsure of the next step in his rehabilitation.
"I feel like I'm where I need to be and headed in the right direction," he said.
Upton brothers lift Atlanta
It took Justin Upton 87 games to hit his eighth home run of the 2012 season. It took him 47 games to tally 12 extra-base hits.
He matched both those marks through the first 14 games this season, leading the National League in both categories entering Thursday night, and has helped turn the Atlanta Braves from a playoff contender to a World Series threat.
The Braves acquired Upton, 25, in an offseason trade with the Arizona Diamondbacks, matching him with older brother and free agent B.J. Upton, 28.
"It's not rocket science," Justin Upton said of his early success. "I'm just going out and having fun. The last few years, I've kind of gotten away from that."
He said he is not putting much pressure on any of his at-bats, which can often be difficult for a high-profile athlete playing in a new city.
"It's definitely fun to be able to play with my brother," he said. "I can't downplay that."
The Braves lineup was average in 2012, and Pirates manager Clint Hurdle said the Upton brothers add speed and power.
"And young speed and young power," Hurdle said. "And they're also pretty good on the other side of the ball playing defense ... "
Pirates reliever Jason Grilli remembers facing B.J. Upton when Upton was playing for the Durham Bulls, Tampa Bay's Class AAA affiliate.
"I was even impressed with him then," he said, recalling one time Upton hit a pitch that Grilli placed in the bottom outside corner of the strike zone and drove it to the opposite part of the ballpark.
And, like the rest of the league, Grilli is impressed by what he has seen from Justin Upton this early in the season.
"Maybe playing with your family member strengthens you to [play well]," he said.
Injured starters near return
Francisco Liriano (fractured right humerus) and Charlie Morton (Tommy John surgery) likely will make three more rehabilitation starts before being ready to join the rotation, Hurdle said. Liriano will make his second rehab start Saturday when he will throw four innings and about 65 pitches for Class AA Altoona.
Following that schedule, Liriano should be ready to join the major league team for a start May 5.
Morton made his first rehab start Thursday night for Class A Bradenton, allowing two earned runs on three hits over three innings. He threw 44 pitches, 33 for strikes, and struck out two batters.
Following that schedule, Morton should be ready to join the Pirates May 8.pirates
Michael Sanserino: email@example.com, 412-263-1722 and Twitter @msanserino.