BOSTON -- Left-handed reliever Daniel Ray Herrera was designated for assignment following Friday night's 10-4 loss to the Red Sox, just two days after he was called up.

Herrera had allowed four earned runs in 1 2/3 innings, including an inning against the Sox on Friday, but after starting pitcher Shaun Marcum exited the game after the first inning with a left hip flexor strain, the Brewers needed a fresh arm in the bullpen.

"If Shaun hadn't gone down, we wouldn't be making this move," manager Ron Roenicke said. "But with Shaun going down early, we have to get a pitcher in here tomorrow with some length just to make sure that we're covered. We need a long guy that can give us two three innings."

Roenicke said the club hadn't decided yet who would replace Herrera.

Before Friday's game, Roenicke had nothing but good things to say about his 5-foot-6 reliever. Herrera is an inch shorter than Royals reliever Tim Collins, who was the shortest player in the Major Leagues on Opening Day.

  • 131 wins
  • 121 wins

"He's small," Roenicke said, laughing. "I mean, a lot of times with these guys it's a different look. It's like facing a guy that's 6-foot-10. He may only throw 90 mph, but it's a different look, and guys don't like it."

Herrera's arsenal includes a fastball, sinker, cutter and a screwball that he taught himself while in college at the University of New Mexico. He only recently learned the cutter, a pitch that has become increasingly popular among Major Leaguers, and throws it only on days when it feels good during pregame catch. But it's the screwball that allows him to get both right- and left-handed hitters out.

"In college, I had a terrible changeup, and I kind of turned it over and it was pronated until it pretty much spun like a curveball," said Herrera, demonstrating the way he throws his screwball, crossing his index finger on top of his thumb and keeping the ball in the back part of his hand. "It took a while to really hone in on throwing strikes and the command of it, but it's been my bread-and-butter pitch."

Fielder begins Interleague Play as DH

BOSTON -- With the Brewers beginning a 15-game stretch of Interleague Play against the Red Sox on Friday night, Prince Fielder was the first to take a turn as the team's designated hitter.

Fielder has played in all 70 of Milwaukee's games this season, though he's hitting .237 in 59 career at-bats as the DH, compared to .282 while playing first base.

"We'll try to alternate," manager Ron Roenicke said. "If [Fielder] needs to do it a couple days, we may do that, but we'll try to just do that today and switch it off the next two."

Roenicke highlighted Ryan Braun and Rickie Weeks as candidates to DH over the next two days.

While the Brewers remain in first place ahead of the Cardinals by one game heading into Friday night, Roenicke said the series with Boston will be important for the club to get back on track.

"You're always trying to figure out why your club goes through the good streaks and the not so good," the skipper said. "And every time it happens and you think you're going to be on a roll, and all of a sudden it stops and you kind of wonder, 'What happened? What's the difference?'

"And I think the really good teams, they have certain things that don't allow themselves to get into long bad streaks, whether it's great starting pitching or great offense. Usually it's great starting pitching. And when I look at our club, I think of our starting pitching. There's no reason we should go through long streaks of not playing well."

Worth noting

• Injured reliever Takashi Saito will make his second rehab appearance in three days when he pitches for Triple-A Nashville on Friday night. Saito pitched a perfect inning Wednesday, throwing 17 pitches and striking out one.

• Craig Counsell was in the lineup at shortstop Friday, as manager Ron Roenicke said he just wanted to give Yuniesky Betancourt a day off. "I think Craig needs to keep playing once in a while," the manager said. "Like I said before, if Craig is hot, he's going to get in the lineup. If Yuni is hot, he's going to stay in the lineup."

• After struggling to keep the Cubs' offense at bay during the late innings in each loss this week, Roenicke said it'll be even more important against a team like the Red Sox. "They've got some guys that I'm never comfortable with," he said. "They've shown through the years that they win games on the last out like it's their job."

• The last time the Brewers played the Red Sox, Milwaukee was swept in a three-game set at Fenway Park in 2008. The Brewers are 1-10 over their last 11 games vs. Boston.

• Red Sox closer Jonathan Papelbon will be inactive during the first two games of the series while serving a suspension for making contact with umpire Tony Randazzo on June 4. Papelbon appealed and reduced the suspension from three games to two.