Funchess revealed why in an Instagram post, citing his family members' experiences with COVID-19 and his desire to sit out for their and his safety.
Per a revised collective bargaining agreement between the NFL and NFLPA, players have the option to sit out the campaign during the COVID-19 pandemic.
Those who voluntarily opt out are eligible for a $150,000 salary advance, per NFL.com.
Higher-risk opt-outs—players who have medical conditions that could make them more likely to have serious complications if they test positive for COVID-19—are eligible for a $350,000 stipend in addition to an "accrued season toward free agency and all benefits and minimum salary credit for a credited season," according to NFL.com.
The former Michigan Wolverine played his first four seasons with the Carolina Panthers and reached the Super Bowl during his rookie year in 2015. The second-round pick's best individual season occurred in 2017 when he snagged 63 passes for 840 yards and eight touchdowns.
The latter two statistics led all Panthers during their 11-5 season, which ended with a 31-26 Wild Card Round loss to the New Orleans Saints.
Funchess played one more year in Carolina before inking a one-year contract with the Indianapolis Colts, but he landed on injured reserve after just one game with a broken collarbone.
He signed with the Packers to help round out the wide receiver corps behind superstar Davante Adams.
Sans Funchess, the team will turn toward Allen Lazard, Marquez Valdes-Scantling, Jake Kumerow and Equanimeous St. Brown. Marcedes Lewis, Robert Tonyan and Jace Sternberger lead the tight end depth chart.
Funchess is one of at least 25 players to opt out as of Tuesday evening, per NFL.com. That list includes New England Patriots linebacker Dont'a Hightower, Pats safety Patrick Chung and Buffalo Bills defensive tackle Star Lotulelei.
Funchess is among 14 voluntary opt-outs, per NFL.com.