Rosenberg had a 6.75 ERA in 13 appearances. He allowed 10 runs (nine earned), seven walks, five home runs and struck out nine in 12 innings after he allowed six runs, seven walks, no home runs and struck out 17 in his final 16 1/3 innings last year. Phillies manager Ryne Sandberg said the biggest difference in Rosenberg is a drop in velocity.
"It's not the same as it was last September," Sandberg said. "He was throwing it 95, 96 mph. He was humping up there. He closed a game. He was pitching in the eighth. But he hasn't had the velocity. I don't know [why]. He doesn't have it yet."
Rosenberg's fastball has averaged 92.6 mph this season, according to FanGraphs. It averaged 94.3 mph in the final two months of last season, and 95.3 mph in 2012.
Sandberg said Rosenberg has been working on a cutter and two-seam fastball to give his ball more movement.
"As he goes along it might be good for him," Sandberg said.
Todd Zolecki is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.