If and when Jeff Green returns to the NBA -- and the encouraging news heading into his heart surgery next week is that he likely will -- he will have plenty of choices as to his next employer.

That's because the Boston Celtics, in a move that was not made public, withdrew Green's qualifying offer in mid-December, right around the time he failed his physical and had his one-year, $9 million contract voided. The move means Green is now an unrestricted free agent. Had the offer not been withdrawn, and the Celtics were under no obligation whatsoever to do so, Green would have been a restricted free agent, with the Celtics able to match any offer he might get from another team.

Asked about the decision on Friday, Celtics general manager Danny Ainge, citing Green's impending surgery, said he preferred not to discuss the matter. He did confirm it, however. It may have been nothing more than a goodwill gesture on the part of the Celtics to Green and his agent, David Falk, who said the team has been "phenomenal" in handling the situation.

"It was not something we expected or bargained for, but coming as it did after such devastating medical news it was almost like an early Christmas present," Falk said.

Falk added that the new collective bargaining agreement rules also may have played a part in the Celtics' thinking as well.

Green is scheduled to have heart surgery Monday at the Cleveland Clinic to treat an aortic aneurysm that was detected in his physical exam. Doctors have given Green a promising prognosis and have indicated that the surgery should allow him to resume basketball, but not until next season.

Theoretically, any team could sign him right now, with the understanding that he would not be available until next season at the earliest. But if no team steps up between now and July 1, Green would join a free-agent class that could include Dwight Howard and Deron Williams, as well as (former) teammates Ray Allen and Kevin Garnett.

From the Celtics' point of view, the withdrawal of the qualifying offer is a bit of a gamble in that it could lead to the departure of the most significant piece of February's trade that sent Kendrick Perkins to Oklahoma City. That would leave the Celtics with nothing to show from the deal, save for a first-round draft pick that belongs to the Clippers and is protected over the next few years.

Then again, Green's NBA future, at present, is murky. And the change in his free-agent status puts Green in the same contractual position he would have been in had he been able to play out this season. Both sides knew that not only would Green be an unrestricted free agent next summer by taking the one-year offer, they also knew he could not be traded without his permission.

Also, the Celtics will still be able to offer Green a longer, more lucrative deal than any other team, either to re-sign him or sign him as part of a sign-and-trade deal, which is what they did last month with Glen Davis.

Prior to the startling discovery of the aneurysm, Green was planning on playing a big role for the 2011-12 Celtics. The team was hoping they'd see a more confident, assertive player who, with the benefit of a brief training camp, would be more comfortable. Green even showed up early to watch film and was ready to go once camp opened. But the red flag from his physical forced him to the sidelines for the first few workouts and, after a second consultation, the aneurysm diagnosis was confirmed and a surgery date set.

Despite the Celtics' voiding of the contract, Green still has been around the team. He was with them for the first road trip in New York and Miami and also joined them in Washington, which is where he went to college. He has talked of being relieved that his situation was discovered when it was, and that he will be able to continue playing in the NBA.

Falk said Green is planning to spend the entire spring in Boston to be around the Celtics after he recovers from Monday's surgery.

Longtime Celtics reporter Peter May is a frequent contributor to ESPNBoston.com.