Following the Red Sox’ 7-5 win over the Blue Jays Friday night at Fenway Park, Stephen Drew still didn’t have a clear idea how severe his right hamstring injury might be. “We’ll see tomorrow,” the shortstop said, “have a better idea of it.” Drew first felt the tightness in the back of his right leg when rounding first base on what was resulted in a fourth-inning double. After being checked on by Red Sox manager John Farrell and trainer Masai Takashi at second base, Drew exited the game. He was replaced by Brandon Snyder, who played third while Jose Iglesias moved over to shortstop. Drew explained that he had never had hamstring issues in his right leg, having previously strained his left hamstring in 2009 (resulting in a trip to the 15-day disabled list). “I haven’t had that many hamstring deals in my career,” he said. “I had one early, but this is nothing like last time I did it. I tore it (then), so I know I didn’t do that. Hamstrings are funny, but I’m staying positive and hopefully it’s maybe one or two games and we’ll go from there. It’s just coming around (first) really tightened up on me.”