An 11th-round draft pick in 2009 out of Western Carolina, Masters has established himself as a versatile southpaw with plenty of deception. A starter in his first two seasons, Masters opened 2011 in the high Class A Lynchburg bullpen before joining the rotation and going 9-5, 3.34 in 23 starts.
He made his Double-A debut in the Mississippi's last game of the season and tossed seven shutout innings at Carolina.
"I was happy to get a taste of what Double-A life was like at the end," Masters said. "The nerves were there, but the outcome of my one start at the end of the season was exciting.
"That outing gave me that last little bit of incentive to train even harder this offseason to make certain I was physically and mentally prepared for this year so that I could open the season in Mississippi."
Masters, 24, achieved his goal and joined lefties Sean Gilmartin and Luis Avilan and righties Zeke Spruill and David Hale in the Mississippi rotation to open the season. He had some inconsistency during spring training while he tweaked his delivery, and some of those same ups and downs were obvious in Masters' first two starts, when he issued eight walks and allowed 10 hits and five runs over 9 1/3 innings.
Some members of the organization believe Masters has a ceiling similar to that of Kris Medlen, a righthander who has served Atlanta as a versatile starter and reliever.
"I was drafted as a reliever," Masters said, "but I've started for the majority of my professional career, which has been great.
"I just want a chance to show that I have the versatility to handle either starting or relieving, based on the needs of the organization. I want to be able to fill whatever void they might have or fit the role where they believe I would have the most success."
• Gilmartin, last year's first-round pick, followed an impressive showing in big league camp by posting a 3.50 ERA and allowing 22 baserunners in 18 innings during his first three Double-A starts.
• Righthander Julio Teheran pitched scoreless ball in starts Nos. 2 and 3 for Triple-A Gwinnett, striking out 11 in 10 2/3 innings. In his first start, he allowed six of 11 batters to reach base and allowed three runs.