The window for NFL teams to sign restricted free agents to offer sheets will close quietly.
Butler will earn $3.26 million in 2020 after carrying a base salary of $645,000 at the conclusion of his rookie pact.
The 26-year-old entered the league as an undrafted free agent in the spring of 2017. Since then, Butler has appeared in every game for New England and started eight, totaling 62 tackles, 11 sacks, seven batted passes and one forced fumble.
Butler recorded a career-high six sacks last regular season on an interior depth chart led by Lawrence Guy and current Detroit Lion Danny Shelton. The 6-foot-5, 300-pound Vanderbilt product saw 473 snaps on defense to go with 98 on special teams in the process.
Patriots offensive lineman Jermaine Eluemunor, a fellow restricted free agent, signed his original-round tender on Thursday.