Whitley, taken with the No. 17 overall pick by the Astros in last year's Draft, appeared in eight games combined last year in the Gulf Coast League and rookie-level Greeneville, going 1-2 with a 4.82 ERA in 18 2/3 innings.
"There's a lot of distractions in pro ball, a lot of ups and downs," Whitley said Tuesday outside the Astros' Minor League complex. "You're happy, you're sad, you're bored. It's just one of those things. Minor League baseball is a crapshoot. You never really know. … Last year was tough. It was a punch in the face. I wasn't really expecting it. You learn, and I'm happy to be out there."
Whitley is a wiry 6-foot-7 at 19 years old and has an impressive arsenal centered around his 92-97 mph fastball and power curveball. He has an easy, repeatable delivery and figures to be able to move steadily through the system in the next few years.
"I'd say the one thing I'm working on right now is persistence, trying to stay persistent in my routine as far as baseball goes," he said. "I've learned that's probably the most important thing I need to be about in pro ball."
Whitley spent the offseason at home in San Antonio getting in shape. He worked out six to seven days a week, including yoga and Pilates. He took off from throwing in the fall and into the new year, got on a weighted ball routine and started throwing off the mound in the middle of January.
"I worked my butt off this offseason," he said. "In terms of physical shape, I'm right there. It's just a matter of getting the arm in shape in Spring Training."
The Astros would like to send him to Class A Quad Cities to spend the bulk of his season, but he wouldn't go to Iowa until the weather warms up later in the spring. Nothing has been decided, though.
"I'm pumped, I'm excited," Whitley said. "I can't wait to go out and play every day, go out every fifth day. I heard it's pretty cold in the first couple of months where I might be reporting, but I'm going to have to deal with that fight."
Brian McTaggart has covered the Astros since 2004, and for MLB.com since 2009. Follow @brianmctaggart on Twitter and listen to his podcast. This story was not subject to the approval of Major League Baseball or its clubs.