By Mike Harrington The Buffalo Sabres' roster is set for Sunday's season opener against the Philadelphia Flyers, and General Manager Darcy Regier confirmed today that 18-year-old center Mikhail Grigorenko will be a part of it. Grigorenko, the Russian who was Buffalo's top draft choice last June and a star of this year's World Junior Championships in his native country, will get his five-game junior tryout.