"I was saving that one for him," Gray said. "I knew I was going to need it.
"I was thinking 'grip and rip' on this one."
Rockies manager Walt Weiss said, "That's what happens when people with different color uniforms step on the field with you. Every athlete gets motivated to compete. He reached back a little bit and added on with his fastball."
Gray, the Rockies' top prospect and the 16th-rated prospect in the Minors by MLB.com, was selected third overall out of Oklahoma in 2013.
Gray struck out 51 in 37 1/3 innings in 2013, his first pro half-season -- a performance that earned him an invitation to big league camp last year. The Rockies sent him to Double-A Tulsa. While his performance was solid -- 10-5, 3.91 ERA, 113 strikeouts in 124 1/3 innings -- he experienced fatigue in his first full pro season. His velocity dropped to a top of 92 mph, and the Rockies shut him down before the Texas League playoffs.
Wednesday, Gray showed off his arm strength.
Gray also showed composure. He walked his first hitter, Brandon Drury, but settled and sailed. His final out was a strikeout of Nick Evans on a four-seam fastball that was 92 mph, but he was more interested in keeping it low in the zone.
"I kind of went to the basics and focused on the target," Gray said. "At first, I was seeing the batter, the catcher, the plate, everything. But after that, I focused on the glove, got my deep breath in and threw."
Thomas Harding is a reporter for MLB.com. Read his blog, Hardball in the Rockies, follow him on Twitter @harding_at_mlb, and like his Facebook page, Thomas Harding and Friends at www.Rockies.com. This story was not subject to the approval of Major League Baseball or its clubs.