The 24-year-old right-hander will be looking to prove his health to the organization, continuing the process of recovering from surgery to remove an aneurysm discovered under his right armpit.
A former first-round Draft selection of the Yankees in 2006, Kennedy was off to a fast start at Triple-A Scranton/Wilkes-Barre this year, going 4-0 with a 1.59 ERA in his first four starts before he felt numbness in his pitching hand.
The procedure was performed in May, and while Kennedy has ruled out pitching in Major League games before 2010, he continues to work out and throw at the club's training complex in Tampa, Fla., throwing fastballs and changeups during bullpen sessions.
Kennedy has appeared in 13 Major League games since 2007, going 1-4 with a 6.14 ERA in 12 starts. He will be joined on the AFL's Surprise Rafters roster by catcher Austin Romine, infielder Brandon Laird and outfielder Colin Curtis.
Romine, 20, made a strong impression on the Yankees this spring and has kept producing at Class A Tampa of the Florida State League, batting .276 with 12 home runs and 70 RBIs through 111 games.
A second-round selection of New York in 2007, Romine -- the son of former big leaguer Kevin Romine and brother of Angels farmhand Andrew Romine -- is considered one of the Yankees' top catching prospects, along with Jesus Montero.
Romine had committed to Arizona State University before signing with the Yankees, so he will finally have his chance to go to the desert, where both his father and brother starred as collegians.
Laird, who turns 22 in September, was hitting .266 with 12 home runs and 70 RBIs through 113 games for Class A Tampa. A 27th round selection in 2007, Laird is the younger brother of Tigers catcher Gerald Laird.
Curtis, 24, was a fourth-round selection of the Yankees in 2006 from Arizona State. He spent time at Double-A Trenton of the Eastern League and Triple-A Scranton/Wilkes-Barre of the International League, batting a combined .246 with six home runs and 42 RBIs through 115 games.
Bryan Hoch is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.