"If you watch some of the better guys, some of the best pitchers -- Andy Pettitte, Mike Mussina -- they all throw two-seamers," said Kennedy, who pitched alongside both starters in 2008. "You look at the positives and I've been watching those guys do it for a long time."
Kennedy, finally given a chance to develop and sharpen his two-seam fastball, struck out five over five innings for his second win in seven Arizona Fall League starts Tuesday as the Surprise Rafters topped the Mesa Solar Sox, 9-2.
"Today was probably the best I've thrown my two-seamer. I have lot more confidence with it," said Kennedy, who made one appearance with New York this season following surgery in May. "I've always said I needed to work on it before and now I've got a real solid chance to see the results. It's really hard during the season, you're trying to compete."
Kennedy held the Solar Sox to a run on five hits and did not walk a batter, throwing 50 of 66 pitches for strikes. He'll bring his new two-seamer -- a fastball that tends to sink and move more than a four-seamer -- to camp in February and, more importantly, show the Yankees he's healthy again.
"Everything health-wise is back to normal," said the 24-year-old, who began the 2009 season with Triple-A Scranton/Wilkes-Barre but was forced off the mound after a month with coldness in his pitching hand. He underwent surgery to remove an aneurysm in his right arm on May 12 and, following a second procedure in August, returned to the field a month later with Class A Advanced Tampa.
"It was real nice to feel good after surgery, and all the way through the rehab, I've had no health issues, so it's good," he said. "My surgeries and everything else went well."
Kennedy finished his AFL stint with a 2-1 record and 4.25 ERA. He struck out 28 batters over 29 1/3 innings and looks to be another versatile arm for Joe Girardi's consideration in Spring Training.
"I'll basically do whatever they tell me, but they haven't talked about it," Kennedy said of his role in 2010. "I'll ask them, but we didn't talk about it a whole lot when I was up there. I know my innings were down this year, so it depends what they want to do."
A healthy Kennedy provides the Yankees with a few options. Pettitte is a free agent and the world champions likely will need to define roles for Joba Chamberlain and Phil Hughes, two right-handed starters who ended the postseason in the bullpen.
Kennedy relied on another Pettitte trademark on Tuesday -- a cut fastball.
"The first couple times around, I was throwing a lot of two-seamers, but I also threw my cutter a lot more today," he said. "Andy's best pitch is a cutter, and watching him throw a two-seamer -- it's a really good pitch, it allows me to utilize other pitches. I don't like to overthrow my four-seamer, but I feel confident I can put that where I want. But if you watch some of the best pitchers, they already have a two-seamer."
The USC product went 1-0 with a 1.59 ERA in four Triple-A starts this season and joined the Yankees when they clinched the AL East. He was only watching on TV, however, when they stormed to their 27th World Series championship.
"It was pretty exciting, it's too bad I didn't get to be there. But, you know, it's pretty exciting to watch," he said. "I got to play in one game and experience the clinching, so it was pretty cool."
Fellow Yankees prospect Colin Curtis and former Royals first-rounder Mike Moustakas hit two-run homers in the seventh after Mets outfielder Nick Evans smacked a two-run blast in the fifth for Surprise. Jarrod Dyson, a 25-year-old Royals outfielder, went 3-for-5 with two RBIs out of the leadoff spot.
Andrew Cashner (2-3), the Cubs' top pick in the 2008 Draft, allowed three runs -- two earned -- on four hits and a walk over three frames.
Danny Wild is an editor for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.