Justin Tuck recently vowed that he would punch any teammate who turns on Tom Coughlin or causes any locker-room trouble because of the Giants’ 0-4 start. But former Giants defensive tackle Chris Canty thinks Tuck should worry about punching somebody else first. “Justin needs to worry about punching opposing offenses in the mouth” Canty now a Ravens defensive tackle said on NFL Network on Wednesday night. “The way you show that you have your coach’s back is by going out there on that football field and performing.” JACOBS IN RUNNING Brandon Jacobs has rushed for just 11 yards on 11 carries since he rejoined the Giants in early September. But the grizzled running back — the lone experienced runner the Giants have left — is going to get plenty of chances over the next few weeks. The Giants’ decision to release third-down back Da’Rel Scott on Tuesday elevates Jacobs into a familiar role. As recently as 2011 he was the Giants’ power back working with Ahmad Bradshaw to give them a solid rushing tandem. And now he will play a similar role behind second-year runner David Wilson. NEW COREY STORY The good news for Corey Webster is that the hip injury that kept the cornerback out of the Giants’ last two games is just fine. The bad news? On Wednesday Webster revealed that he has been dealing with a groin injury all along. That is why he has spent the last two weeks repeatedly saying that his hip was “fine” and then being too injured to even travel with the team.