PHILADELPHIA, July 29 (UPI) -- The Philadelphia Phillies obtained pitcher Roy Oswalt from the Houston Astros Thursday in exchange for three players and cash considerations.

Oswalt, who has spent his entire 10-year career with the Astros, will make his first start for Philadelphia Friday in Washington.

The Phillies sent pitcher J.A. Happ to Houston along with two prospects -- outfielder Anthony Gose and infielder Jonathan Villar.

Oswalt has close to $5 million remaining on his 2010 contract and is due to make $16 million next season. There is also a mutual option in his contract for 2012 that will bring him $16 million if he plays for the Phillies or a buyout of $2 million.

Oswalt has had little run support with the Astros this year while compiling a 6-12 record with a 3.42 ERA.

Philadelphia General Manager Ruben Amaro said at a news conference Thursday the team had done "due diligence" in checking out the soreness Oswalt has experienced in his back this season. Amaro said there was no structural damage in Oswalt's back.

Oswalt's career record is 143-82 with a 3.24 ERA in 303 appearances. He was one win away from equaling the Houston career victory record owned by Joe Niekro.

He joins Roy Halladay and Cole Hamels in giving Philadelphia a high-quality starting rotation. The two-time defending National League champion Phillies began their contest against Washington Thursday on a seven-game winning streak and trailed first-place Atlanta by three games in the NL East.