Dolphins sign right tackle Austin Jackson to contract extension

Last offseason, the Miami Dolphins declined to pick up right tackle Austin Jackson’s fifth-year option. Now, they’ve made sure to lock him in through his seventh year. The Dolphins signed Jackson to a three-year contract extension, according to a league source Thursday morning. The deal is reportedly worth $36 million with a max value of $39 million and $20.7 million guaranteed, according to …