The Cleveland Cavaliers are requesting more trade assets from the Boston Celtics after a physical reveled Isaiah Thomas has a hip injury. Thomas of the Boston Celtics is pictured laying up the ball against the Atlanta Hawks during the 2016 NBA Playoffs at Philips Arena on Apr. 26, 2016 in Atlanta, Georgia. Getty Images

The Boston Celtics-Cleveland Cavaliers mega-trade remains on hold after a physical revealed All-Star guard Isaiah Thomas has not fully recovered from an injured hip. The Cavaliers continue to seek additional compensation from the Celtics and could reject the trade if their request isn't met, while leaving Thomas in limbo ahead of next year's free agent market.

As of Sunday, the two teams have yet to re-engage in talks. The Cavs and Celtics agreed to a trade involving All-Star Kyrie Irving for Thomas, Jae Crowder, Ante Zizic and Brooklyn's 2018 first round pick last week. But, once the Cavs became privy to Thomas’ injury, they requested that the Celtics send over additional assets, according to ESPN’s Adrian Wojnarowski.

It’s still unclear when Thomas would return to basketball activities. The Celtics have maintained that they were transparent about Thomas’ health.

The deadline for the players being traded to report and submit to a physical is 10 a.m. EST on Wednesday and the deadline to pass the physical is 10 a.m. EST on Thursday. However, both teams can agree to extend the deadline if interested.

Celtics president Danny Ainge conceded during a conference call with reporters that Thomas’ age, contract and injury may have influenced their decision to trade him. A hip injury sidelined Thomas during the 2017 NBA Playoffs, which he has yet to have surgically corrected.

It’s worth noting that the Celtics hold a wealth of possible assets they can use to solidify an Irving trade, including six first-round draft picks over the next two drafts. Boston may be able to use protected picks from the Los Angeles Lakers, Memphis Grizzlies and L.A. Clippers. Boston also has multiple second-round draft picks, which they could include in a deal.

If the deal fell apart, it could be awkward for all parties involved. Irving, 25, who requested the trade last month, would have to return to a Cavs team after requesting a trade. Thomas, who played for the Celtics in the wake of his sister's death, would go back to Boston knowing that he and some of his teammates are expendable.

Thomas, 28, will be an unrestricted free-agent in the summer of 2018. He is coming off his best season, averaging 28.9 points per game on 46.3 percent shooting.

Many Celtics fans found have disappointed that Boston traded away the prized point guard, including a child who asked about Thomas during an event Friday. Celtics head coach Brad Stevens was on hand and answered the young fan’s inquiry.

"What he did in Boston the last two-and-a-half years have been incredible," Stevens said. "I said earlier what he’s meant to me, what I think of him, how great he’s been in the locker room, what kind of a teammate he’s been. Those are all really, really, really hard decisions, and that’s the hard part of being a professional basketball coach."

Wojnarowski said that the events surrounding the trade and the injury have "unfairly" damaged Thomas' value around the league. The NBA insider suggested that ambiguity over Thomas' health could mean he receives less as a free agent.

The trade also adds a wrinkle to the Cavs' hopes of re-signing superstar LeBron James, who has been rumored to be considering leaving the team next summer.