The best argument for paying Jimmy Butler? The Sixers probably can’t afford to replace him. | David Murphy

Five years and $188 million are a lot for an NBA team to commit to any single player, let alone one who brings with him the multitude of uncertainties that Jimmy Butler does.

From longevity (he’ll be 30 next season), to fit (with Ben Simmons), to track record (witness the arc of his tenure with his previous two teams), there are plenty of variables to consider when determining whether it would be wise for the Sixers to dole out the maximum amount of money that they will be allowed to pay their free-agent-to-be when he opts out of his contract in July.

But while Butler is eligible to sign for five years and $188 million, a more pertinent question for the Sixers might be whether he is worth four years and $96 million, because that is roughly the amount of money that they will have at their disposal to replace him if they bid him farewell. And when you look at the situation from that perspective, you should begin to understand what might be the strongest argument for doing whatever it takes to bring him back next season.

In a nutshell, the Sixers will find it awfully difficult to use the dollars that they would have spent on Butler to sign a player or combination of players who replaces his production. In a smaller nutshell: The Sixers’ best possible roster in 2020 is very likely one that has Butler on it.

The longer version:

In a world where the Sixers hope to keep their current starting five together, they would likely enter free agency with a payroll of around $125 million, which is $16 million more than the salary-cap threshold, and would thus limit them to signing a player with their mid-level exception, along with any veterans willing to play for the minimum.

Included in that $125 million figure are:

1) Salaries for Joel Embiid, Ben Simmons, Jonah Bolden and Zhaire Smith.

2) Salary cap holds for Butler and Tobias Harris that they must keep clear to retain both players’ Bird Rights (which enable them to offer one more guaranteed year and 3 percent more in annual raises than the other 29 teams).

3) A salary cap hold for JJ Redick, which they’d need to retain to keep his Early Bird rights, which would allow them to go over the cap to re-sign him.

4) A salary cap hold for 120 percent of the slot money assigned to their No. 24 pick in the June draft.

5) A salary cap hold for the mid-level exception ($9.1 million)

6) A roughly $2.7 million charge for the three roster spots not occupied by any of the above.

» READ MORE: The Sixers must confront the Jimmy Butler dilemma | Bob Ford

For the sake of the argument, let’s say that the Sixers end up bringing Redick back at the same $12.5 million salary, a few million less than his cap hold. As long as the Sixers maintained the rest of their holds, and were willing to go into the luxury tax, they’d be in a position to enter the 2019-20 season with a starting five of Simmons, Embiid, Butler, Harris and Redick; and a bench that includes Smith, Bolden, a mid-level veteran free agent, the No. 24 pick, and some combination of young players and veteran minimum guys.

Here’s what that payroll would look like before any Butler decision:

As you can see, they’d still be about $12.6 million over the cap, with Butler already counting for $30.7 million (the amount of his hold), which is only $2 million less than his salary would be in Year 1 of a max contract.

If the Sixers decided to move on from Butler, they could renounce their Bird Rights and clear that $30.7 million. They’d also have an additional $4.3 million cleared by downgrading from the mid-level exception to the room exception, the former of which cannot be used by a team that uses cap space to sign a free agent (instead, teams that use cap room can go over the cap to sign a player for a maximum of a two years and a Year 1 salary of $4.7 mil). That would put them in position to offer four years and $90.7 million (or a maximum of $22.5 million in total Year 1 salary) to some other free agent, or combination of free agents (this is corrected from an earlier version of this story, which had the number at four years and $78 million).

On last year’s free-agent market, that would have enabled them to sign someone such as Marcus Smart for four years and $53 million and Joe Harris (two years, $8 million), or Jerami Grant (three years, $27 million) and Avery Bradley (two years, $25 million).

You can finagle the numbers all you want, but the Sixers simply are not going to be able to choose to sign another All-Star-caliber player with the money that they have at their disposal to sign Butler. They wouldn’t be enough for a veteran max contract player. Barring some improbable turn of events, any decision not to re-sign Butler would be a decision to replace him with someone in a tier that last year featured players such as Smart and Will Barton and, on a shorter-term deal, Trevor Ariza.

Essentially, if Butler leaves, the Sixers will either need to count on addition by subtraction — a tough case to make given what we saw in the postseason — or on a dramatic shakeup in which Redick also leaves (which would give them roughly $30 million to spend on a couple of replacements).

This, more than anything else, is the reason the Sixers thought it prudent to trade all they did for Butler and Harris during the season. And it’s the reason that keeping the whole gang together is probably their most realistic path toward optimizing their roster for 2019-20.