The 49ers did not let their most prized free agent get away.
The team and Ian Williams reached agreement on a five-year deal early Wednesday that kept the nose tackle off the open market, a league source said. Williams’ deal is between $5 million and $6 million per year.
The source would not go on record because he does not have the authority to comment on the matter.
Meanwhile, the Vikings signed guard Alex Boone as soon as free agency began. Boone and the 49ers failed to agree on a contract extension in 2014, and it became clear he would move on when he had the opportunity. He and the 49ers had only cursory contract discussions since.
In Minnesota, Boone will work under offensive-line coach Tony Sparano, who was the 49ers’ tight ends coach last year. His departure leaves the 49ers searching for a starter at left guard. Other prominent free agents at the position – including Kelechi Osemele, Brandon Brooks and J.R. Sweezy – also were taken off the market Wednesday, although the team has a visit set up Thursday with Cardinals free-agent guard Ted Larsen, 28.
The 49ers agreed to terms on a one-year deal with a quarterback, Thaddeus Lewis, who was on coach Chip Kelly’s roster in Philadelphia last year. Lewis, 28, entered the league in 2010 as an undrafted rookie and was not active for any Eagles games in 2015. His most prolific season came in 2013 when, as a member of the Buffalo Bills, he started five games, threw for 1,092 yards and four touchdowns while also tossing three interceptions.
Despite his age, the 26-year-old Williams was voted a team captain last season and is one of the few healthy veterans along a suddenly thin defensive line. Pro Football Focus rated him as one of the top run-stopping interior linemen in the league last season.
Williams, who had suffered injuries in 2013 and 2014, finally was healthy last year and had his best season. He played 57.8 percent of the team’s defensive snaps and finished with 45 tackles, a sack and a forced fumble. Unlike in previous seasons where the 49ers’ nose tackle came off the field in passing situations, the quick-footed Williams played a significant number of snaps in the nickel defense.
He appeared to be the 49ers’ free agent they simply couldn’t lose.
If Williams had departed, the team would have been left with 2015 preseason standout Mike Purcell at the position. Williams, Purcell, Quinton Dial and Arik Armstead are the only healthy defensive linemen currently on the roster who played a significant number of snaps last year. Glenn Dorsey tore his ACL in November and may not be ready for the start of the season.
Receiver Anquan Boldin, running back Reggie Bush and kicker Phil Dawson officially became free agents Wednesday. So did defensive lineman Tony Jerod-Eddie, who was scheduled to be a restricted free agent. The 49ers did not tender Jerod-Eddie, instead offering him a modest deal that he has not yet signed.