The Boston Celtics didn't pay Grant Williams this summer, and it could come back to haunt them.

After a 2021-22 campaign that saw the former first-round pick excel in an important 3-and-D role, Williams was hoping to lock up a new contract extension with the C's. Unfortunately, the deal never came to fruition and he is set to become a restricted free agent in 2023.

While Boston can still match anything for their fan-favorite forward, the cost might be higher than the front office would like. According to NBA writer Michael Scotto of HoopsHype, Williams could receive offers in free agency hovering around $18 million annually. Based on the reports of what the Celtics tried to pay him, this would be a significant increase in price, per Scotto:

“During extension talks with Grant Williams, the Celtics never offered more than $50 million guaranteed over four years, league sources told HoopsHype. As I previously reported on HoopsHype, Williams would’ve taken a deal for $14 million annually.”

Since extension talks broke down, Williams has done everything right on the court. Right now, he's shooting a spectacular 50% from beyond the arc and posting 9.5 points and 4.8 rebounds per game. With this stellar play, the 23-year-old has raised his value, and other teams like the San Antonio Spurs and Detroit Pistons are reportedly inquiring about him already.

If the C's paid Williams earlier, Williams' hot start would be perfect. Instead, Boston has to think about the future and what it may have to do without a reliable 3-point shooter who can also guard well. Of course, there are replacement options, yet they could be out of the Celtics' desired price range. Of course, Boston could also just pay up and deal with the extra luxury tax bill.

For now though, “The Batman” is committed to the Celtics and eager to help them return to the NBA Finals. What the summer will hold is up in the air, but right now Williams has a lot to offer the red-hot Celtics.