Von Rosenberg surrendered just one hit over six innings as Class A West Virginia beat Savannah, 4-3, in 12 innings Wednesday. He struck out five and did not figure into the decision.
The 20-year-old right-hander retired the first 17 batters of the game before Alonzo Harris singled up the middle to end his perfect-game bid in the sixth. Von Rosenberg recovered to whiff Darrell Ceciliani to end the frame and his night at 61 pitches.
"Really tonight I had everything, I was locating very well," Von Rosenberg said. "I was keeping them off balance, and overall, it was a good outing. The fastballs I wanted to locate in I did, and they saw enough of those that it opened up enough of the plate and opened up my offspeed pitches."
A sixth-round pick by the Pirates in 2009, Von Rosenberg has struggled in his first season in the South Atlantic League, posting a 3-7 record with a 7.04 ERA in 19 games. He had allowed nine earned runs over his last 7 1/3 innings for the Power. Von Rosenberg said the difference was going after hitters.
"Tonight, I was pitching to make them hit the ball," the 6-foot-5 Louisiana native. "Sometimes I fall into pitching around guys and it traps me because I fall behind. Just forcing them to put a bat on the baseball, that was my mentality tonight."
Von Rosenberg was committed to attend Louisiana State University before being given a $1.2 million signing bonus by Pittsburgh. Despite a 1-6 record for State College, the Pirates' No. 9 prospect rewarded the club's faith with a 3.20 ERA in 13 starts for the Spikes last season.
Given Von Rosenberg's struggles this season, he is looking to prove himself to Pittsburgh down the stretch.
"I definitely want to finish strong because I haven't had a great start and I haven't gotten on a roll," he said. "I need some sort of consistency and I need to keep it even-keel and be that guy the Pirates know can go six innings. I haven't done that and it's definitely something that needs to happen."
Casey Sadler (4-4) earned the win after tossing two hitless innings of relief. Justin Ennis allowed a hit in a scoreless 12th for his second save.
Gonzalez Germen tossed five one-hit innings, fanning four, for the Sand Gnats. Ronny Morla (1-2) was tagged with the loss after allowing a run on one hit in one inning.