Rosenbaum in Rockies' mix for middle relief

GOODYEAR, Ariz. -- One has to be looking for left-hander Danny Rosenbaum's locker at Salt River Fields at Talking Stick to find it. It's hidden from the center of the room by a partition.

It's a fitting place for a guy who could be a big part of the Rockies when the season starts but could very well not be here at all. As a Rule 5 Draft pick, Rosenbaum must make the squad and stick throughout the season or be offered back to the Nationals -- his former club -- for $50,000.

Rosenbaum has put up a nice argument for himself in the competition for a middle-relief spot. He threw a scoreless ninth inning -- he walked a batter with one out but forced a double-play grounder -- as the Rockies beat the Reds, 5-1, on Friday night. Rosenbaum is 2-0 with a 2.25 ERA in eight innings covering eight appearances.

Rosenbaum has liked the opportunity but admits it's odd not knowing how long he'll be around.

"I've been a little bit more to myself because I don't know what's going to happen, but I didn't want to just sit here and be by myself, reading the newspaper," said Rosenbaum, 25, who was never in Major League camp with the Nationals and hasn't pitched above Double-A, although he has a 2.84 ERA through four Minor League seasons. "I wanted to interact, meet all these new guys and get to know everyone. Everyone's been real welcoming. That's made my job a lot easier."

Having never competed for a big league job and never as a reliever, Rosenbaum said he received help from Nationals middle reliever Craig Stammen.

"When I found out that was the role I was going to be put in, I tried to pick his brain because he was one of the best middle-relief guys in the game last year," Rosenbaum said. "We threw some bullpens and I tried to seek out some things.

"He said, 'Don't change anything. They're big league hitters for a reason, but don't make it bigger than it is. Just go out and do your thing. You're here for a reason. Just compete.'"

Thomas Harding is a reporter for MLB.com. Read his blog, Hardball in the Rockies, and follow him on Twitter @harding_at_mlb. This story was not subject to the approval of Major League Baseball or its clubs.