Updated

ST. LOUIS (AP) Hard-throwing pitching prospect Tyler Glasnow will make his major league debut for the Pittsburgh Pirates against the St. Louis Cardinals on Thursday night.

The 6-foot-8 right-hander has a 1.78 ERA in 96 innings at Triple-A Indianapolis and runs his fastball up to 99 mph. He was a fifth-round pick in 2011 and has ranked among the Pirates top prospects since breaking out in Class A in 2013. The team announced the move Wednesday.

The 22-year-old Glasnow will be the second Pittsburgh starter to make his debut in three days after Steven Brault got a no-decision Tuesday after giving up two runs in four innings against the Cardinals.

The rotation spots opened in part because Jameson Taillon - another prized pitching prospect who debuted this season - went on the disabled list Sunday with right shoulder fatigue.