PHILADELPHIA (CBS) — Following Friday night’s game against Atlanta, the Phillies placed right-hander Roy Oswalt on the 15-day disabled list with lower back inflammation, retroactive to April 27, Senior Vice President and General Manager Ruben Amaro Jr. announced. To fill his spot on the 25-man roster, the Phillies recalled right-hander Scott Mathieson from triple-A Lehigh Valley.

In five starts with Philadelphia this season, Oswalt is 3-1 with a 3.33 ERA. The 33-year-old has held opposing hitters to a .212 average while striking out 21 batters in 27.0 innings. He took the loss in his last start, April 26 at Arizona, snapping a career-high 10-game winning streak, the longest by a Phillies pitcher in the last 35 years.

Mathieson, 27, has gone 0-0 with a 4.97 ERA in eight games with Lehigh Valley this season. In 11 career games with the Phillies, including eight starts, Mathieson is 1-4 with a 7.62 ERA in 39.0 innings.

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