Former Miami Dolphins defensive tackle Earl Mitchell has reached a four-year deal with the San Francisco 49ers, according to ESPN and multiple reports.

The deal is worth $16 million total with $6.5 million guaranteed, $5.5 million in the first year, per ESPN and multiple reports.

It's a big pickup before the league year officially starts March 9.

The Dolphins released Mitchell on Feb. 16 in a cost-cutting move. He was due to earn $4 million next season.

He played in only nine games last season as he was put on injured reserve after Week 1 because of a calf injury and then activated on Nov. 10 when the Dolphins used their designated to return spot on him.

Mitchell, who finished with 18 tackles, was inconsistent in stopping the run and the Dolphins were 30th against the run last season.

Mitchell, 29, has 38 career starts in stints with the Dolphins and Houston Texans.

Adding Mitchell before free agency begins gives the Niners a leg up on bolstering their ailing run defense. The Niners gave up 2,654 rushing yards in 2016, 371 more than any other team and a franchise record for futility. They also yielded 25 rushing touchdowns and 4.84 yards per carry, both of which ranked last in the NFL.

With new coordinator Robert Saleh in place, the Niners are planning to switch to a 4-3 defensive scheme that puts an emphasis on stopping the run. Mitchell is likely to play nose tackle in that defense, especially with defensive tackles Glenn Dorsey and Chris Jones scheduled for free agency. The only other candidates for that position on the current roster are Quinton Dial and Mike Purcell.