Rivera shrugs off player’s Twitter rip, says he’ll last season

At 2-8 with a pair of scintillating road trips to Philadelphia (3-7) and Kansas City (1-9) on tap, the Panthers have gone well past frustration. Now, they’re not even frustrated with the frustration. After blowing an 11-point fourth-quarter lead to lose in overtime to the Buccaneers, Panthers defensive end Charles Johnson tweeted out his problem…