The Arizona Diamondbacks activated right-hander Max Scherzer from the 15-day disabled list in time to start against the St. Louis Cardinals.

Scherzer had been sidelined with inflammation in his right deltoid.

To make room on the roster, the Diamondbacks optioned right-handed reliever Billy Buckner to Triple-A Reno on Tuesday. Buckner had allowed seven earned runs in four innings, a 15.75 ERA.

Scherzer was named to the starting rotation over the winter. The 24-year-old Missourian flashed his potential in 2008 season.

In his major league debut against Houston last April 29, Scherzer retired the first 13 men he faced. He lost all four of his big league decisions but had a 3.05 ERA in 16 games, including seven starts.

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