Denver, CO -- (Sports Network) - The Florida Marlins selected the contract of top pitching prospect Chris Volstad from Double-A Carolina on Sunday.

Volstad tossed two scoreless innings and pick up the victory in his big league debut as the Marlins downed the Colorado Rockies, 10-5.

The 6-foot-7 right-hander was the 16th overall pick by the Marlins in the 2005 draft. In 15 starts at Double-A this season, Volstad is 4-4 with a 3.36 earned run average. The 21-year-old has struck out 56 and walked 30 while allowing only 86 hits in 91 innings.

To make room for Volstad, after Saturday's 12-6 loss to the Rockies the Marlins optioned lefty reliever Taylor Tankersley to Triple-A Albuquerque. In 24 games this season, Tankersley has struggled to an 0-1 record and an 8.64 ERA, allowing 16 earned runs in 16 2/3 innings.

Tankersley last pitched on Friday, allowing three runs in one-third of an inning in Florida's 18-17 loss to Colorado.