Per Marc Stein of the New York Times, Johnson is a "prime target" for the Nets with DeAndre Jordan and Nicolas Claxton not traveling to Orlando.
Jordan announced on June 29 that he wouldn't be traveling with the Nets to Orlando, Florida after testing positive for the coronavirus.
The Nets announced Claxton would be unavailable for the rest of this season after undergoing shoulder surgery to repair a torn labrum on June 24.
Johnson hasn't played in the NBA this season after spending the previous two years with the Philadelphia 76ers. The 33-year-old's last appearance was in Game 6 of the Eastern Conference semifinals against the Toronto Raptors on May 9, 2019.
In 51 games for the Sixers last season, Johnson averaged 3.9 points and 2.9 rebounds per contest.