Jaguars’ cornerback Rashean Mathis has been ruled out of the team’s Week 12 game against the 49ers with a groin injury, according to the Twitter page of beat writer Michael C. Wright. Mathis missed last week’s game as well with the injury, so it must be serious if he has already been ruled out on Monday. This is good news for Alex Smith and company, with Michael Crabtree getting the biggest boost out of the receivers.