The New England Patriots entered free agency with the most salary cap space in the NFL and are spending big Monday, especially on the defensive side.

The Patriots are poised to add three impact players to bolster their defense, agreeing to contracts Monday with free agent defensive tackle Milton Williams, cornerback Carlton Davis III and linebacker Robert Spillane.

Williams agreed to a four-year, $104 million deal, sources told ESPN. Davis agreed to a three-year, $60 million contract that includes $34.5 million fully guaranteed, sources told ESPN's Adam Schefter. Spillane agreed to a three-year, $37.5 million contract that includes $20.6 million guaranteed, a source told ESPN's Jeremy Fowler.

The Patriots also are adding to the offensive side, having agreed to a three-year, $24 million contract with tackle Morgan Moses, a source told ESPN's Mike Reiss. Moses' deal has a maximum value of $28.5 million.

Williams is coming off his best statistical season, finishing with 5 sacks, 10 quarterback hits and 7 tackles for loss for the Philadelphia Eagles' top-ranked defense in 2024.

He ended on a high note, sacking Patrick Mahomes twice in Super Bowl LIX, including a fourth-quarter strip sack that he recovered himself to halt any comeback hopes for the Kansas City Chiefs.

Williams, 25, was selected in the third round of the 2021 draft out of Louisiana Tech. Part of a deep defensive line rotation that has featured players such as Fletcher Cox and Jalen Carter, Williams started 19 games over four seasons for the Eagles, compiling 11.5 sacks and 29 QB hits.

Davis, 28, was acquired by the Detroit Lions last year via trade with the Tampa Bay Buccaneers for a 2024 third-round draft pick. The Lions also received 2024 sixth-round and 2025 sixth-round selections as part of the deal.

Davis was extremely productive in 2024, totaling 56 tackles and two interceptions on the year before suffering a season-ending jaw injury in Week 15 against the Buffalo Bills.

He spent his first six seasons in Tampa Bay after being selected in the second round as the 63rd pick in the 2018 NFL draft out of Auburn.

Davis has 11 interceptions, 84 passes defended and 380 tackles in seven seasons.

In 2024, Spillane, 29, started all 17 games for the second straight season with the Las Vegas Raiders.

He had at least 10 tackles in eight contests last season. In a Week 17 loss to the Los Angeles Chargers, Spillane tallied 16 tackles in 75 defensive snaps.

Spillane finished the season with 158 tackles, 14 quarterback pressures and a pair of sacks. Since joining the Raiders in 2023, Spillane has collected 306 tackles, fourth most during that span, behind Zaire Franklin (Indianapolis Colts), Bobby Wagner (Seattle Seahawks/Washington Commanders) and Roquan Smith (Baltimore Ravens).

Six-foot-1, 229-pound Spillane signed with the Titans as an undrafted free agent in 2018, when now-Patriots coach Mike Vrabel was in his first year as head coach with Tennessee. Spillane played in two games for the Titans before getting waived. In 2019, Spillane signed with the Pittsburgh Steelers. During Spillane's four-year stint with the Steelers, he played a reserve role, starting in 16 of his 50 games with the club.

Overall, Spillane has totaled 497 tackles, 8.5 sacks, 6 interceptions and 19 passes defended in 86 career games (50 starts).

Moses started 14 games at right tackle for the New York Jets last season, finishing 32nd out of 65 qualified tackles in pass block win rate (89%, the NFL average). At 34, he has lost some of his lateral quickness, but he's a savvy veteran with a polished technique.

Durability is his strong suit, though Moses has displayed signs of wearing down the past two seasons. He missed three games last year (knee sprain) and three with the Baltimore Ravens in 2023 (torn pectoral).

Before that, Moses went eight straight seasons (mostly with Washington) without missing a game. He's also known for his toughness.

When Moses sprained an MCL last season, he slept in a hyperbaric oxygen chamber to expedite the healing process. He wound up missing less time than anticipated. Late in the year, he injured his left wrist in pregame warmups in Week 14, took a painkilling shot and played the first half before the pain became too great. Nevertheless, he started the following week despite significant swelling and discomfort.

Last season was his second stint with the Jets, who acquired him in a March 2024 trade with the Ravens. He signed with New York in 2021 following his release by Washington after seven seasons, then went on to start two seasons for the Ravens at right tackle.

ESPN's Tim McManus, Eric Woodyard, Ryan McFadden and Rich Cimini contributed to this report.