Now that Gordon Hayward has joined the roster, Tom Penn details how cap space and luxury taxes may cause Boston to make hard decisions next season. (1:03)

The Boston Celtics have been aggressively trying to create enough salary-cap room to give Gordon Hayward the four-year, $128 million maximum contract he agreed to by discussing trades involving Marcus Smart, Jae Crowder and Avery Bradley, sources told ESPN.

The Jazz and Celtics discussed on Wednesday the possibility of including Crowder in a sign-and-trade agreement for Hayward, sources said, which would be cap beneficial for Boston.

Ultimately, Hayward himself will have to agree to a sign-and-trade, which could be perceived as a farewell gift to the franchise that drafted him and developed him into an All-Star. Crowder had been publicly critical of the Celtics' pursuit of Hayward during the 2016-17 season, in part, perhaps, because he'd be the player most impacted by Hayward's arrival.

The Celtics have to make a complicated series of moves to create enough space to sign Hayward to the full max. But because the salary cap did not rise as much as projected, they likely will have to trade one or more of those three players to sign Hayward. Sources told ESPN that Boston has discussed trades involving Smart, Crowder and Bradley with at least half-dozen teams on Wednesday.

The Celtics have to make a complicated series of moves to create enough salary-cap room to sign Gordon Hayward to the full max. Photo by Brian Babineau/NBAE via Getty Images

The process of clearing contracts and salary-cap space started Tuesday, when Boston renounced Kelly Olynyk. But even if the team renounced the rights to Jonas Jerebko, James Young and Gerald Green, waived Jordan Mickey, left 2016 first-round pick Guerschon Yabusele in Europe this season and traded Demetrius Jackson's partially guaranteed contract and Terry Rozier, Boston would have $29,444,533 to sign Hayward, which is still about $300,000 short of his max.

Crowder -- who finds himself in a logjam at small forward with the Hayward signing, 2017 No. 3 draft pick Jayson Tatum and 2016 lottery pick Jaylen Brown -- would appear to represent the most logical move. He is owed $6,796,117 this year, $7,305,825 next year and $7,813,533 in 2019-20.

Bradley is in the last year of his contract, at $8,808,898, and is extension eligible. Smart is in the final year of his rookie contract, at $4,538,020, and also is eligible for an extension.

The Celtics' payroll could soar to $150 million next summer if Bradley, Smart and Isaiah Thomas are all brought back, and Boston could have a luxury tax bill of more than $70 million.

ESPN's Bobby Marks contributed to this report.