Jason Anderson of the Sacramento Bee reported the update and noted there's "mutual interest" between the sides heading into the NBA's moratorium period. Marc Stein of the New York Times confirmed the Kings are "definitely" a suitor in the Horford sweepstakes. However, despite the planned offer, Sam Amick of The Athletic reported the Kings are "under the impression" Horford will likely sign elsewhere.
He's also scheduled to meet with some "mystery teams" after the market opens before making a decision about his future Monday or Tuesday, per Adam Himmelsbach of the Boston Globe.
John Gambadoro of Arizona Sports 98.7 Radio reported one of the mystery teams is the Philadelphia 76ers, who could offer the veteran post player "over $100 million." Amick later reported Philadelphia's interest in Horford is "very real."
Kevin O'Connor of The Ringer added that "some league executives" believe the Celtics are a mystery team for Horford as well. However, O'Connor noted "keeping Horford's rights would require a number of complicated maneuvers, including a double sign-and-trade involving Kemba Walker and Terry Rozier. It wouldn't be easy."
The 33-year-old Dominican Republic native is one of the league's most quietly productive stars. He averaged 13.6 points, 6.7 rebounds, 4.2 assists and 1.3 blocks while shooting 53.5 percent from the field, 36 percent from three-point range and 82.1 percent on free throws during the 2018-19 season.
He ranked 18th in the NBA in ESPN's Real Plus-Minus despite playing career-low minutes (29 per game) on an overcrowded Boston roster, which also limited his offensive touches.
At season's end, Horford said he wanted to see how the Celtics' front office handled its initial offseason moves before deciding whether to return.
"It's something that I haven't even stopped to think about," he told reporters. "I've enjoyed being here in Boston. Just have to wait and see what we're going to do as a team. And it's steps that the management is going to do moving forward, and continue to get better."
Boston entered the year with championship aspirations but fell well short of those expectations when it was eliminated by the Milwaukee Bucks in the second round of the playoffs.
Horford may seek a new team where he'll take on a more marquee, defined role, particularly at the offensive end, after seeing his playing time dip this past season. And money will be a factor, too.
In Sacramento, he'd immediately become the team's unquestioned top frontcourt option and get to play alongside one of the NBA's most promising backcourts in De'Aaron Fox and Buddy Hield.