How the Celtics' end-of-season cap gymnastics will work

SAN FRANCISCO — The Boston Celtics just inked two players to 10-day contracts: Dalano Banton and John Tonje.

This was the first in a string of eventual moves they will make to remain in compliance with the NBA's roster rules while also staying under the tax line.

BSJ commenter cc8772850 asked a great question on a recent article:

If they wait to the last day to convert Harper, how much will his prorated contract cost? When is that last day?

So, I figured I would answer that question to the best of my abilities.

First, let me start with this: I am not a cap expert. Far from it.

If you want very specific, in-depth details about what the Celtics are likely to do from here on out, Spotrac's Keith Smith and HoopsHype's Yossi Gozlanboth explained it well. (And with a far more extensive knowledge of the cap specifics than I have.) That said, here's a rough outline of how Boston will approach the end of the season.

The opportunity to get under the apron was not one Brad Stevens expected to have this season.

“After the Vuc trade, we saw that as an opportunity,” Stevens said at a post-trade deadline press conference. “But next year, if there's something that we look at and we say, we got to take advantage of it right now, then we're going to try to take advantage of it. Bill's been really clear with that. I think we saw, again, the tax for me, was just, there was an opportunity with two days left before the trade deadline. We didn't necessarily think we'd be there.”

Once that happened, Boston traded Chris Boucher, Josh Minott, and Xavier Tillmanin three separate deals. That string of moves got them to $842,292 below the tax line.

Fast forward to today, February 19, and the Celtics were forced to sign two players to 10-day contracts.

The NBA's minimum roster size is 14. But with the trades Boston made at the deadline (and the conversion of Amari Williams' two-way contract to a standard deal), their roster size sat at 12.

Teams can only be under the 14-man minimum for 14 days at a time, and a max of 28 days in an entire season.

So, the Celtics waited until exactly 14 days after the February 5 deadline to reach the necessary 14-man minimum.

Banton and Tonje's 10-day contracts will last until February 28. Then, the Celtics can go another 14 days without having to sign two more guys. By then, it would be March 14, leaving 30 days left in the season.

At that point, they could sign two players to small enough deals to stay under the tax line.

This season, 10-day contracts for veteran players are $131,970, and for rookies, they are $73,153.

So, Banton and Tonje's 10-day contracts are worth a combined $205,123. Subtracting that from $842,292 leaves the Celtics $637,169 below the tax line.

After that, with 30 days left, the Celtics will be able to sign Ron Harper Jr. and Max Shulgato prorated contracts for the rest of the season and have just enough room to add one final player to be their 15th man (if they signed him on the final day of the regular season).

Again, for a full breakdown with exact numbers, go read this article by Gozlan.

But that's the general idea.

There may be other ways for the Celtics to manage the situation, but that's the one Gozlan outlined, which seems like the most straightforward.