Within hours of Brad Penny's release, the list of teams interested in the veteran right-hander's services was already starting to take shape.

The Denver Post reported early on Thursday morning that the Rockies -- who have questions in the back end of their starting rotation -- have expressed interest, and The Miami Herald later said that the Marlins -- who could use a veteran starter to give them a boost in the National League playoff chase -- are also among the teams intrigued.

According to The Herald, the White Sox, Rays and Rangers are also in play. ESPN.com says the Giants have interest, the Minneapolis Star-Tribune indicates the Twins are intrigued and the New York Post reports the Yankees are in the mix.

Penny, released by the Red Sox on Wednesday night, would clear waivers by Monday, and teams would then be able to sign him to a pro-rated minimum salary, amounting to about $85,000.

Any team that picks him up before the waiver period ends would have to pay the roughly $1 million remaining on his deal with the Red Sox.

Penny, who pitched for Colorado manager Jim Tracy while with the Dodgers in 2005, went 7-8 with a 5.61 ERA in 24 starts this season. He won just one of his last 11 outings, and in four August starts, the 31-year-old has struggled to an 0-3 record and an 8.31 ERA.

Penny, with 101 wins and a 4.18 ERA in 10 big-league seasons, missed significant time in '08 because of shoulder problems. After four full seasons with the Dodgers, the Oklahoma native signed a one-year, $5 million deal with the Red Sox last offseason.

Upon his requested release, Penny told The Boston Herald he'd like to sign on with a playoff contender by the end of the month so he's eligible to land on a postseason roster.

The Rockies trail the NL West-leading Dodgers by three games but lead the Wild Card race by three games, with the Marlins 4 1/2 out. The Rangers are 2 1/2 out and the Rays are 4 1/2 behind in the AL Wild Card standings, and the White Sox are 4 1/2 games behind in the AL Central.