Even as his Knicks are shut down because of the coronavirus pandemic, James Dolan is getting attacked in a print ad by a basketball organization.

In an aggressive attempt to promote its June 27 outdoor festival at Flushing Meadows, the Big3 — a three-on-three professional basketball league — appeared to brand Dolan as having racial animus in a full-page ad that ran in Friday’s Post.

The Big3 advertisement contains, at the top, a quote from Dolan’s chief antagonist, Charles Oakley, stating, “It’s a plantation over there.’’

Under it is another quote from freshly minted Dolan enemy Spike Lee, who shouted at Garden security guards in early March: “If you want to arrest me like Oakley, go ahead.’’

Under a Big3 logo, the ad contains the message: “Players are not property. The fans are our guests.’’

The advertisement comes at a time when Dolan has agreed to compensate Garden workers for this week’s missed Big East Tournament games and future Knicks and Rangers games, according to a Garden source.

“We’ve already taken immediate action this week and are working on a longer-term plan,’’ a Garden source told The Post.

At the beginning of the season, the Knicks’ top five front office personnel, as well as their head coach, were black.

The Big3 is staging a 12-team, six-game event at the USTA Billie Jean King National Tennis Center — site of the U.S. Open. The games will be played at Louis Armstrong Stadium — the secondary tennis venue.

The USTA, which runs the U.S. Open, distanced itself from the plantation ad.

“We are not the promoter of the event, and we were unaware of the ad,” USTA spokesman Chris Widmaier told The Post. “We will discuss the future positioning of this event with the promoter.”

An industry source said there have been no plans to cancel as of yet because of the global health crisis.

Big3 organizers declined to comment on the advertisement and its backstory. The Garden also had no comment.

Oakley made his “plantation” comment on ESPN earlier this month after Lee and Dolan feuded over which entrance the Knicks superfan was allowed to enter the Garden. Oakley went on to say NBA commissioner Adam Silver should intervene, as he did with former Clippers owner Donald Sterling after an audio tape was discovered of him making derogatory racial comments.

Oakley has been a Big3 head coach, and former Knicks Amar’e Stoudemire and Nate Robinson played for the local Tri-State team last season. Robinson has committed to play this season.

Ice Cube, a Big3 co-founder, announced in January the league no longer wants to be seen as a haven for retired NBA players, lowering its age requirement to 22.