For a bullpen that ranked 27th in the Major Leagues last year with a 4.19 ERA, the Phillies can use as many productive arms as they can find. Rosenberg's performance likely warrants a spot in the 'pen, but he's not taking anything for granted in the final week before Opening Day.
"It's important to just finish strong and keep building on what I've been working on," Rosenberg said on Monday. "I'm not trying to look too far ahead as far as a roster spot. I'm trying to keep working and be consistent and be ready for the season to start."
Rosenberg said he's been able to slow the game down this year, which he attributes in part to spending two months in the big leagues at the end of '13. He did not allow a run over eight appearances in August and earned his first career save in September, impressing the Phillies coaching staff along the way.
"That was huge, just for confidence alone," Rosenberg said. "The biggest thing was slowing the game down, not trying to do too much."
Rosenberg likely won't be closing games for the Phillies in April, but he's shown value as a reliever who can go multiple innings and fill almost any role.
"Over the last few years, I've really done kind of everything," Rosenberg said. "I've been a multiple-inning guy, I've closed a bit in Triple-A, last year I was throwing the eighth inning a lot. I feel comfortable doing whatever."
Todd Zolecki is a reporter for MLB.com. Austin Laymance is a reporter for MLB.com. Follow him on Twitter at @jalaymance. This story was not subject to the approval of Major League Baseball or its clubs.