The San Francisco 49ers decided not to pick up the contract option for Earl Mitchell, which will make the veteran defensive tackle a free agent about a month before the start of the new league year and give him a jump on searching for a new team.

The 49ers signed Mitchell to a four-year deal in February of 2017, and he has spent the past two seasons with San Francisco. During that time, Mitchell registered 61 combined tackles, a sack, and four passes defensed. He started each game of the 2017 season and the first 12 of 2018 before the 49ers decided to sit the veteran in favor of second-year defensive tackle D.J. Jones.

Defensive coordinator Robert Saleh, who is in Mobile, Alabama for the Senior Bowl with the rest of the 49ers staff, discussed the decision on Wednesday to move on from Mitchell.

"Earl's been a fantastic asset to this entire organization with all the things he's done," Saleh said via NBC Sports Bay Area before the South squad's Wednesday practice. "It's an opportunity for other guys to try to step up. It will not be easy to try to replace him, for sure."

Mitchell was inactive for the 49ers' final two games of the 2018 season as Jones racked up 13 combined tackles in his four starts at the end of the year.

"I thought he did a good job," Saleh said of Jones. "Obviously, he still has to get better. There's going to be a lot of competition for him."

Jones won't be handed anything and, as always, the 49ers hope to create competition for the starting job alongside their Pro Bowl defensive tackle, DeForest Buckner. Jones likely welcomes the opportunity to compete for the spot this offseason.

"I'm already my biggest critic," Jones told 49ers Webzone in May of 2017. "I've got to be the best, so I've got to do things to make myself the best. I just want to work as hard as I can. If starting is in my future, let that be. It depends on how hard I work for it."