Jay Cutler’s reputation in the NFL is founded on his ‘‘cannon for an arm.’’ But in Marc Trestman’s offense it’s going to take more than that. ‘‘The best thing that Jay did [against the Oakland Raiders on Friday] is he dropped back and got rid of the ball quickly’’ Bears offensive coordinator Aaron Kromer said. ‘‘He knew where to go. He knew how to throw it and he knew who he was getting it to by play and by [the] coverage that he was seeing. That was a strong step in the right direction.’’ It remains to be seen if Cutler will blossom into an elite quarterback in Trestman’s offense. But he seems more comfortable with his coaches his teammates and especially his offensive line than he ever has been. A year ago the subject of the offense in particular the offensive line drew only a tepid hopeful response. ‘‘We can only do as much as [the line] can handle’’ Cutler said at the time. Fast forward to Tuesday. Though he was typically conservative Cutler sounded almost excited about the offense’s potential. ‘‘We’re headed in the right direction’’ Cutler said. ‘‘Coach Trestman and coach Kromer and all of the guys have done a good job of piling a lot of stuff on us and then limiting it back and trying to figure out what we’re good at and what we can be successful at. It’s been fun to see the progress the guys have made and how hard they’ve worked and studied throughout the offseason.’’ Asked if the Bears have found their best five offensive linemen Cutler seemed satisfied that whether the current starters are the best the Bears can win with them. ‘‘I just know that the five guys in front of me have been doing a really good job the last couple of games’’ Cutler said.