Simpson is returning from his six-game suspension for violating the substance abuse policy.
Bethea wound up leaving Thursday night’s game with a shoulder injury. The fact that he’s already being ruled out for the year is a clear indication that the 49ers believe it’s a pretty serious injury for Bethea.
Bethea, 31, is in the second year of his four-year, $21 million contract that included a $5 million signing bonus. He stands to make base salaries of $3 million (2015), $4.5 million (2016), and $5.25 million (2017) over the remainder of the agreement.
His 2015 season comes to an end with him appearing in seven games and recording 44 tackles, one sack and two pass defenses for the 49ers.
Simpson, 29, signed a two-year, $1.73 million contract with the 49ers back in March and stands to make base salaries of $745,000 and $885,000 over the next two years.
He hasn’t appeared in an NFL game since the 2013 season when he caught 48 receptions for 726 yards receiving and a touchdown.