Adrian Wojnarowski breaks down the possible action that Cleveland could take with Isaiah Thomas and the Celtics depending on Thomas' medical evaluation. (0:59)

What do Cavs do next with Thomas? (0:59)

In the aftermath of issues resulting from Isaiah Thomas' physical examination on Friday, the Cleveland Cavaliers and Boston Celtics are planning a telephone call for Saturday to discuss the status of the teams' blockbuster trade, league sources told ESPN.

The proposed deal sending Cleveland's four-time All-Star guard Kyrie Irving to the Celtics for Thomas, Jae Crowder, Ante Zizic and a 2018 first-round pick via Brooklyn has been thrust into uncertainty with medical questions surrounding Thomas' injured hip, league sources told ESPN.

It is possible that Cleveland could request further compensation from Boston before it'll approve the trade, league sources said. Cleveland has until Thursday to make a final decision on approving the trade, sources said. Cleveland can veto the deal based on a failed physical, sending players back to their respective teams.

Thomas took the exam in Cleveland on Friday before flying back home to the West Coast, league sources said.

"It's a very sensitive situation," one source involved in the process told ESPN.

Irving, who had requested a trade from Cleveland, is set to take his physical with the Celtics on Saturday, league sources said.

The deadline to report and submit to a physical for the players involved in the trade is 10 a.m. Wednesday, and the deadline to pass the physical is 10 a.m. Thursday, per league rules. However, if both teams mutually agree to extend the deadline, they can.

Thomas has been rehabilitating a hip injury that ended his season in the Eastern Conference finals, and sources have told ESPN that the All-Star guard has yet to begin a regimen of running this offseason.

Boston doctors had decided that Thomas' hip did not require surgery and prescribed a summer regimen of rehabilitation and rest.

Celtics general manager Danny Ainge, when asked whether Thomas' injury played a part in making the trade for Irving, told reporters: "Some."

ESPN's Dave McMenamin contributed to this report.