Now, after bouncing between starting and relieving his first few professional seasons, he has settled into a relief role and taken off.
The 6-foot-4, 210-pound righthander split the 2009 season between low Class A Savannah and high Class A St. Lucie, combining to go 5-3, 2.86 in 79 innings while striking out 84. Opponents hit just .168 against Stinson in the Florida State League, while his groundout-to-flyout ratio was 1.88. Stinson then compiled a 3.65 ERA in 12 relief innings in the Arizona Fall League, though he walked 11 batters.
"I'm using my sinker and forcing groundballs," Stinson said. "I had never really been a strikeout guy. I guess I had more strikeouts this year. I don't know if it's coming out of the pen, just having a different mentality—you only have one or two innings to 'blow it out'—or if it was developing my slider.
"In years past, my slider and curveball were basically the same speed. Last year in Hawaii (Winter Baseball), me and (pitching coach) Rob Ellis worked on it and got it to be more of a slider than a slurve.
"I've really fallen in love with my slider. Rob has got me throwing it the right way."
Stinson's fastball sat at 91-93 mph in Arizona, with an occasional 94 or 95. He's now throwing his slider at 83-84 mph, while his curveball is 77-78 mph.
Stinson, 21, said he particularly enjoyed picking the brains of AFL teammates who already had appeared in the majors, including Ian Kennedy, Mike Dunn and Matt Harrison, about the differences in approaching hitters at higher levels.
As for mechanics, Stinson believes one key for him will be to continue to work to keep his front shoulder closed.
"Basically, just not rushing," he said. "Whenever I rush, the ball goes arm-side, of course, and the sinker runs a little bit too much."
• Righthander Clint Everts, 25, signed a big league contract with the Mets. Everts went 8-1, 1.65 with six saves last season as a Nationals farmhand, primarily at Double-A Harrisburg.
• Catcher Josh Thole finished second in the Venezuelan League's batting race after hitting .381/.470/.568 in 44 games for Caracas. He left Caracas a couple weeks before the end of the season to begin preparing for spring training.