Two days after the Ravens were flagged for two penalties involving defensive players leading with their helmets, Harbaugh said he is remaining open-minded about how the NFL intends to remove helmets out of tackles. “The officials on the field, they expressed, ‘It’s tough,’ ” he said. “It’s a new rule for them, and all these new rules always kind of get worked out in the preseason. So we just have to see what they can actually see and what they can’t see, and I told our guys, ‘There are going to be some called that they’re going to come back and say shouldn’t have been. And there are going to be others not called that should have been.’ We’ve just got to tackle the right way – with our heads up, see what we tackle, and use our shoulders and not use our head as a weapon. That’s what we’re striving to do.” … Harbaugh said he, defensive coordinator Don “Wink” Martindale, outside linebacker Terrell Suggs, punter Sam Koch, Yanda, quarterback Joe Flacco, long snapper Morgan Cox, kicker Justin Tucker and Mosley traveled to Canton to attend Ray Lewis’ Hall of Fame induction ceremony before returning in time for Sunday’s practice scheduled for 8:40 a.m.