The National Basketball Players Association is strongly considering filing a grievance with the NBA after the Detroit Pistons voided a trade over concerns about Houston Rockets forward Donatas Motiejunas' back, league sources told Yahoo Sports.

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The Pistons voided a three-player trade with the Rockets on Feb. 22 after Motiejunas failed a series of medical examinations on his surgically repaired back. Motiejunas has since been cleared medically by the Rockets and has played in five games. Sources close to Motiejunas believe the voided trade could damage his status as a restricted free agent next offseason.

Donatas Motiejunas has played in five games with the Rockets since the voided trade. (NBAE/Getty Images) More

Motiejunas had back surgery in April. Before the trade with Detroit, he had not played a game for the Rockets since Dec. 31 after having back soreness. The Pistons acquired Motiejunas and guard Marcus Thornton from the Houston Rockets on Feb. 18 in exchange for a first-round pick and center Joel Anthony.

"Medical clearance was not given on all players and the trade is being rescinded," Pistons general manager Jeff Bower said in a statement four days after the deal.

Detroit's decision also instantly voided a trade sending Anthony and a Denver Nuggets' second-round pick to the Philadelphia 76ers.

Motiejunas has since questioned the validity of the Pistons' decision, telling Basketnews.Lt in his native Lithuania that he was "screwed."

"The team doctor simply says whether you pass or don't, although they may not do any checks," Motiejunas told the website. "Those 48 hours actually just let the team decide whether they want you or not. The Pistons announced I did not pass the medical, although I surely did pass it and played even before it. I just got screwed. The injury was a pretense to call of the trade. They changed their minds."

Pistons president and coach Stan Van Gundy responded by saying the trade "was too much risk" because of Motiejunas' back concerns.

"Look I feel bad for him, too, because I understand his point in terms of his value and everything else," Van Gundy told Michigan Live. "But we felt we had to make the decision we made."

Motiejunas' representatives believe Van Gundy should not have spoken publicly about their client's medical situation. NBPA executive director Michele Roberts and a union spokesperson declined comment.

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