From the Sabres website:
Buffalo Sabres GM Darcy Regier announced today the Sabres have reassigned forward Zack Kassian to Portland of the American Hockey League. Kassian was Buffalo’s first-round selection (13th overall) in the 2009 Entry Draft, and signed a three-year entry level contract with the Sabres in November.
The 20-year-old Kassian just completed his fourth year of junior hockey, collecting 16 points (6+10) in 16 playoff games with the Ontario Hockey League’s Windsor Spitfires. This follows a regular season that saw Kassian finish with 77 points (26+51) in 56 games with Windsor. Kassian also won a silver medal with Canada at the 2011 IIHF World Junior Championship in Buffalo.
The 6'3 winger finishes his OHL career with and 72 goals, 194 points, and 358 PIM, including 28 fights, in 214 games with Peterborough and Windsor.