Defensive tackle Malcom Brown is leaving the Patriots after signing a three-year, $15 million contract with the Saints.

The Patriots selected Brown in the first round of the 2015 NFL draft, but declined to pick up his fifth-year option last offseason.

The 6-2, 320-pounder was a big piece of the Patriots' defensive line, playing 44 percent of the defensive snaps.

The Patriots helped fill the void left by Brown's departure by agreeing on a two-year deal with Mike Pennel, a run-stuffing defensive tackle. The 6-foot-4, 330-pounder spent the last two seasons with the New York Jets. He made 27 tackles while starting 7 of 16 games last season.

New England added to its thin wide receiver core by signing Maurice Harris and Bruce Ellington.

Ellington, 5-foot-9, 200 pounds, spent last season with the Texans and Lions, two teams with coaching ties to the Patriots. Ellington, known as an inside receiver with experience returning punts and kickoffs, totaled 31 receptions for 224 yards and one touchdown in seven games last season.

The 6-foot-3, 200-pound Harris appeared in 12 games, including seven starts, for the Washington Redskins last season. Like Ellington, Harris has experience in the slot. The 26-year-old tallied 28 catches for 304 yards in 2018.

The Patriots also signed free-agent safety Terrence Brooks, who spent the last two seasons with the Jets. Brooks, 5-foot-11, 196 pounds, was selected by the Ravens in the third round of the 2014 NFL Draft. The 27-year-old is known as a strong special teams player.

Matt LaCosse, a 6-foot-6, 255-pound tight end who appeared in 15 games for the Denver Broncos last season, signed a two-year deal with the Patriots on Thursday. Following the departure of former Patriots tight end Dwayne Allen, LaCosse will now compete for the No. 2 role behind Rob Gronkowski. LaCosse has 27 receptions for 272 yards and a touchdown over the course of his career.