Rockies call up Oswalt, demote Francis

Roy Oswalt will return to a major league mound for the first time in more than eight months when the Rockies face the Washington Nationals on Thursday, with Colorado officially selecting the veteran hurler's contract from Double-A Tulsa.

Oswalt, a three-time All-Star with 163 career victories in the majors, was signed to a minor league contract by the Rockies in May. The 35-year-old went 3-2 with a 2.16 earned run average in five appearances with Tulsa to prepare for the starting assignment in Tuesday's matchup.

The right-hander spent last season with the Texas Rangers, but was not re- signed after posting a career-worst 5.80 ERA in 17 games (nine starts) and allowing 79 hits and 11 home runs over 59 innings.

Oswalt recorded back-to-back 20-win campaigns with the Astros in 2004 and 2005, but has gone just 13-13 with a 4.32 ERA while pitching for Philadelphia and the Rangers over the past two seasons.

The Rockies also optioned Jeff Francis, the second-winningest pitcher in franchise history, to Triple-A Colorado Springs in a corresponding move. To make room for Oswalt on the 40-man roster, pitcher Chris Volstad was designated for assignment.

Francis, a 17-game winner during Colorado's run to its only World Series appearance in 2007, has struggled mightily this season. The 32-year-old lefty went 2-5 with a 6.58 ERA in 11 starts and was rocked for eight runs and 10 hits over six innings in his most recent outing, an 8-3 loss at Toronto on Tuesday.

Volstad, who won a career-high 12 games for the Marlins in 2010, allowed 10 runs and 19 hits over 8 1/3 innings in six relief appearances with Colorado earlier this season.