Running back Brandon Bolden also is planning to opt out of the season, a source told ESPN. Starting offensive tackle Marcus Cannon, fullback Danny Vitale and reserve offensive lineman Najee Toran earlier decided to opt out for the Patriots.
According to an agreement approved by both the league and the NFL Players Association, players considered high risk for COVID-19 can earn $350,000 and an accrued NFL season if they choose to opt out. Players without risk can earn $150,000 for opting out.
Hightower, 30, became a first-time father on July 16 and told teammates Devin and Jason McCourty on their "Double Coverage" podcast this week, "I don't have any words to describe it. Asking what to look forward to and expect, it was that and then some."
In a statement shared on social media Tuesday, Hightower said it wasn't an easy choice but "I do feel that it's the best decision for my family at this time."
Nicknamed "Mr. February" by head coach Bill Belichick because of his knack for delivering big plays in Super Bowls, Hightower was set to enter his ninth NFL season -- all with the Patriots.
A three-time Super Bowl champion and team captain, the 6-foot-3, 260-pound Hightower traditionally calls the defensive signals and was going to be relied upon as much as ever this season after the free-agency departures of linebackers Kyle Van Noy and Jamie Collins.
This was the final year of Hightower's contract, and he was scheduled to earn a base salary of $8 million. The contract will now toll to the 2021 season.
Hightower's foundation annually raises money for the American Diabetes Association, which has significant meaning to him as his mother, L'Tanya, was diagnosed with Type 2 diabetes. Hightower keeps a picture of his mother at his locker.
Chung had agreed to a two-year extension with the Patriots in May that included a $2 million signing bonus and base salary of $1.1 million. While the move was made to help the team create salary-cap space, it also provided Chung with up-front cash and reflected his status as a lock to be on the roster, likely starting alongside Devin McCourty.
Chung, 32, was set to enter his 12th NFL season, 11 of which he's spent with the Patriots. His ability to play closer to the line of scrimmage and match up with opposing tight ends provided Belichick with the flexibility he often covets.
Similar to Hightower, Chung spoke earlier this week about expecting his second child.
On the field, his void could create a fast track for rookie Kyle Dugger, the team's second-round selection, to play more. Free-agent signee Adrian Phillips could also project to that role if he decides to play.
Bolden, 30, was set to enter his ninth NFL season and eighth in New England. He is a core special-teams player who provides valuable depth on offense.
Bolden was set to earn $1.3 million in base salary in 2020, which was the final year of his contract. That will toll to 2021.
Sports radio WEEI in Boston first reported Bolden's decision.