The Dallas Cowboys have picked up the fifth-year option on defensive back Byron Jones' contract and it's worth $6.2 million in 2019.Jones played the last two seasons at safety but is moving to cornerback in 2018. He split time at both positions as a rookie in 2015 after the Cowboys used their 27th overall pick on him out of Connecticut.By moving Jones to safety the club was able to save $2.8 million on the fifth-year option for him.