CHANGES ARRIVED for the struggling Phillies offense more than 2 weeks ago, when Carlos Ruiz' suspension ended and Delmon Young was activated off the disabled list in the span of 48 hours.

The Phillies' rotation has also undergone a makeover, albeit one they rather would have avoided. John Lannan and Roy Halladay were both placed on the DL with Jonathan Pettibone and Tyler Cloyd taking their respective spots in the starting five.

But the one area that the Phillies haven't addressed is one that's been a problem spot for a good chunk of the first 6 weeks. The pitchers who won jobs out of spring training to make up the middle of the bullpen remain despite some lackluster results.

"The guys in the middle have been mediocre," general manager Ruben Amaro Jr. said Friday in Phoenix.

The ugly numbers:

* The Phillies' relief corps has a collective 1.40 WHIP (walks and hits per inning pitched), which is the fourth worst mark in baseball.

* The bullpen has a .761 opponents' OPS. Only Houston and St. Louis have higher numbers.

* The opposition has a collective .337 on-base percentage when hitting against Phillies relievers.

The back end of the pen - Jonathan Papelbon, Mike Adams and Antonio Bastardo - has been largely effective, as expected. But the middle relief - veteran Chad Durbin, rookie Phillippe Aumont and lefties Jeremy Horst and Raul Valdes - have been at best inconsistent and at worst ineffective.

Asked to be the bridge between the starters and the back-end relievers, the middle of the pen has instead played the role of a road in need of reconstruction: Phillies relievers have inherited 42 runners this season. They've allowed 20 of those runners to score.

The 48 inherited-score percentage is the worst in baseball.

"Listen, we have to get the guys to perform," Amaro said. "If they don't perform, we'll make changes. But they've gone in fits and starts. There have been times when they pitch really well and there have been times when they haven't pitched well. Kind of like our club."

Unlike the impossible task of fixing a lineup filled with high-paid veterans and a farm system thin with near-ready replacements, the bullpen can be altered from within. The Phils went to spring training 3 months ago rife with relief arms.

One of those arms, Justin De Fratus, was added to the major league roster on Saturday. De Fratus handled his only assignment of the weekend with aplomb: he struck out Arizona's best hitter, Paul Goldschmidt, in a tie game in the ninth inning on Sunday.

De Fratus, however, was only added to the roster because the Phils have room for an extra arm; they don't need a fifth starter for another week, thanks to a gluttony of off-days.

But when the Phillies do add a fifth starter again (before May 21), that doesn't mean De Fratus will be shipped out, either.

The aforementioned foursome of Durbin, Aumont, Horst and Valdes has a collective 5.53 ERA. They've allowed 66 hits in 57 innings.

The Phils have flexibility with both Aumont and Horst - they can be optioned to Triple A. They don't have the same flexibility with 35-year-olds Durbin and Valdes.

"Chad's situation - his last time or two have been better," Amaro said. "But he's a terribly slow starter. We have to stay with him and hope he continues to get better."

Durbin struck out two batters in a perfect eighth inning of a 4-3 loss to the Giants on Wednesday.

It was his only appearance on the Phils' seven-game road trip and he's pitched just twice in May. In April, Durbin had a 7.00 ERA and allowed nine of 12 inherited runners to score.

In a weekend when the Phils largely avoided their middle relief, thanks to sterling starting pitching, Horst, like Durbin before him, also quietly sneaked in an encouraging outing. Horst struck out two of the three batters he faced in a perfect eighth inning of Sunday's come-from-behind win in Arizona.

Horst had walked four batters in his previous three appearances.

"I was a little off with the fastball," Horst said. "But we're working on it, it's an easy fix."

Walks have also stacked up for Aumont: He has 10 with 12 strikeouts in 11 innings. But Aumont's strikeout stuff often helps him escape bouts of wildness, a l a Bastardo.

"It's not shocking," pitching coach Rich Dubee said of Aumont, who has racked up walks at every level he's pitched. "He's going to have to pitch over some walks, that's who he is. [But] he's got strikeout stuff and he's got groundball stuff. He has a hell of a sinker."

On the farm, no one has exactly jumped out as a potential candidate for the middle of the major league bullpen.

Lefthander Jake Diekman has walked 20 batters in 17 innings. Fellow lefty Joe Savery's numbers have been superb, but he's already been optioned back to Triple A Lehigh Valley after two brief stays with the Phils this season.

Righthander Mike Stutes got off to a slow start with the IronPigs, but hasn't allowed a run while striking out nine and walking two in his last six appearances (9 2/3 innings). At Double A Reading, 24-year-old lefthander Mauricio Robles has impressed, going 2-0 with a 1.35 ERA while striking out 29 and walking nine in 12 games (20 innings) through Sunday.

For now, it appears Amaro will continue to practice patience with his current "mediocre" middle relief corps.

"If those guys [in the minors] were better, or better options, then we'd consider them," Amaro said. "But right now, they're not. They could be. They are certainly options. We're looking for excellence. And consistency. We're kind of up and down."

Today on PhillyDailyNews.com, a vintage photo of the time when Mike Schmidt needed to wear a disguise at the Vet.

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