Mavs fans are helping Dirk get back the money he’s left on the table.

One of the issues with the NBA’s salary cap is that it encourages players to take less money than they’re worth, allowing their teams to spend the extra cash on players they might not otherwise be able to fit under the cap.

No one knows this better than Dirk Nowitzki, who’s making only $5 million in each of the next two seasons. That’s one-third of Timofey Mozgov’s salary and half of Jon Leuer’s.

So in a display of gratitude, one appreciative Mavs fan came through at Friday’s practice to help Dirk make up the difference.

“You been taking discounts the past six years to help the team bring talent and a title,” the fan wrote. “LUNCH IS ON ME BIG FELLA.”

If Dirk’s smart he’ll have Mark Cuban take him to lunch and have the billionaire boss pay for it. Pocket that $20 for his (hopefully distant) retirement.