Beacon Journal wire services The Detroit Lions’ Calvin Johnson said he suffered nerve damage from two big hits in a September loss to the Minnesota Vikings that’s made it tough for him to grip the football. Johnson, who missed practice all of last week and hasn’t practiced this week because of a lingering knee injury, said the nerve problems have subsided though he’s still dealing with some aftereffects. “Taking those hits, they’re real violent,” Johnson said. “They definitely have a lot of lingering impact on whether it be your neck or your head in [Jahvid Best’s] case. It can do a lot of stuff.” Johnson dropped a touchdown pass late in the first half of the Lions’ 20-13 loss to the Vikings at Ford Field when safety Harrison Smith hit him in the sternum with his right shoulder. In the fourth quarter, Johnson took a helmet-to-helmet hit from linebacker Chad Greenway that knocked him temporarily out of the game. Johnson said he suffered a concussion from the Greenway hit, though Lions coach Jim Schwartz said for the second time on Thursday that wasn’t the case. Greenway was fined $21,000 for the hit.