SURPRISE, Ariz. -- With the Astros possessing an improving stock of young starting pitchers in their system, they decided prior to last season to move the power arm and swing-and-miss slider of 6-foot-5 right-hander Jonas Dufek to the bullpen.
The results were promising, as the 25-year-old appeared in a combined 50 games between Class A Advanced Lancaster and Double-A Corpus Christi and posted a 9-2 record with a 3.19 ERA, 74 strikeouts and 64 hits in 67 2/3 innings.
"It was a huge season for him," said Class A Quad Cities pitching coach Dave Borkowski, who has been working with Dufek in the Arizona Fall League. "He came on big in the end and really solidified that back end for Corpus. He's a big kid, he's a horse, he's a bulldog. He wants the ball every day."
Dufek has appeared in seven games for Peoria in the AFL and has allowed eight hits and three earned runs while striking out 12 batters in 9 1/3 innings. He's put himself in position to compete for a bullpen spot at Triple-A Oklahoma City, perhaps with a move to Houston on the near horizon.
"He's a big, durable arm," Astros farm director Quinton McCracken said. "He throws from a downhill plane. He's just taken to that relief role for us. He really came on strong after starting the season in Lancaster and just really blew through Lancaster and went to Corpus and didn't miss a beat. He ended up closing out some very critical games there in the second half of the season."
Dufek, drafted in the ninth round out of Creighton in the 2011 First-Year Player Draft, features a 90-95-mph fastball to go along with his power slider, which is his best pitcher, and a changeup that he's been trying to refine in Arizona. He credits Lancaster pitching coach Don Alexander with helping his move to the 'pen go as smoothly as possible.
"It's a different mentality going out there for three outs," Dufek said. "About halfway through the year, it kind of clicked and really worked for me since then."
Dufek's transition to Corpus went so smoothly because the hitter-friendly conditions of Lancaster and the California League force pitchers to keep the ball down in the zone. He appeared in 14 games for the Hooks and was 7-0 with four saves and a 3.19 ERA in 19 1/3 innings.
"That was awesome," he said. "I went up to Corpus and had some good success right away and was able to build off that, and [manager Keith] Bodie kept putting me in some good roles, and I was able to come though in some big situations for us."
Dufek, who was drafted the June before general manager Jeff Luhnow was hired, has noticed how much the system has improved the last three or four years and is glad to be a part of the Astros' promising future.
"I really like it," he said. "They draft guys that want to win and know how to win. It's guys that are ready to compete and are working their way up. We're going to make a difference."
Brian McTaggart is a reporter for MLB.com and writes an MLBlog, Tag's Lines. Follow @brianmctaggart on Twitter.