The Brooklyn Nets have signed Houston Rockets restricted free-agent forward Donatas Motiejunas to a four-year and likely $35 million offer sheet, league sources told The Vertical.

The terms of the offer sheet are rife with protections against recurring back problems that have sidelined Motiejunas and could make it even more palatable for the Rockets to match and retain the 7-footer. The contract delivers the ability to void the final two years of the contract, as well as an opportunity to bail on the second season before the end of the 2016-17 season, league sources told The Vertical.

The offer sheet has Motiejunas earning $5 million upon the signing of the contract, and the team has to decide by Jan. 10 whether to pay him another $3.5 million for the remainder of the 2016-17 season, league sources said.

By March 1, the team has to pick up the option for $9 million owed to Motiejunas for the 2017-18 season, sources said.

The final two years of the contract are non-guaranteed, league sources said, which means the team can cut Motiejunas loose without paying the balance of the contract. Before the 2018-19 and 2019-20 seasons, there’s a July 7 trigger date to make a decision on Motiejunas’ deal. Each of the four years includes $1 million in likely bonuses, and $500,000 in unlikely bonuses, sources said.

The Nets delivered the offer sheet electronically to the Rockets on Friday night, and Houston has until midnight Tuesday to match the offer sheet and retain Motiejunas.

Concerns over recurring back issues – which included surgery to repair a ruptured disk in 2015 – impacted the interest NBA teams had in signing Motiejunas, 26, to an offer sheet over the summer.

If acquired, Nets general manager Sean Marks and coach Kenny Atkinson view Motiejunas as a power forward playing beside center Brook Lopez.

Houston had been offering a deal in the $8 million range annually, but talks had been sparse between the sides for months.

Motiejunas, who played 37 games a year ago following surgery, and the Rockets had been unable to come to terms on an agreement, causing the 7-footer to miss training camp and Houston’s 12-7 start to the regular season. Coach Mike D’Antoni has been eager to incorporate Motiejunas into the Rockets’ frontcourt and join the current No. 4 seed in the Western Conference.

The uncertainty around Houston’s willingness to agree to a long-term deal with Motiejunas was because of his back issues. Motiejunas was examined by Nets doctors recently, league sources said, and the results gave comfort to Brooklyn to move forward with the offer sheet.

For the Nets, this is the third restricted free agent offer sheet executed under Marks. July offer sheets to Portland guard Allen Crabbe (four years, $75 million) and Miami guard Tyler Johnson (four years, $50 million) were matched. With a franchise devoid of draft picks and talent, Marks has been determined to find creative ways to improve the Nets’ roster.

Taking a shot at Motiejunas is a pre-emptive move on next summer’s free agent market.

The Rockets had a three-way trade that would’ve sent Motiejunas to Detroit voided last season. The Pistons doctors failed Motiejunas on his physical exam because of the back.

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