Teletovic left Thursday night's 123-84 loss to the Los Angeles Clippers at Staples Center after experiencing shortness of breath and was taken to a hospital.
"Our first thoughts are with Mirza and his family," Nets GM Billy King said Friday in a statement. "We are very fortunate that our medical staff, along with the ER staff at the California Medical Center in Los Angeles, were able to diagnose the problem. I have visited with Mirza this morning, and he is in good spirits as he begins his treatment and recovery."
A battery of tests -- including a CT scan -- revealed the seriousness of his condition. Teletovic will remain hospitalized in Los Angeles to undergo further testing and begin receiving blood thinners, the team said. He will return to the New York area upon being cleared. The official medical term for what Teletovic has is bilateral pulmonary embolus.
Teletovic had tweeted after the game that he was OK:
I had a small problem, but now everything is ok... Thx all fans from Bosnia, Spain and USA for support— Mirza Teletovic (@Teletovic33) January 23, 2015
Teletovic had gone to the locker room accompanied by trainer Tim Walsh late in the second quarter after logging eight minutes.
"He could have gotten on the plane and he could have actually died," coach Lionel Hollins said. "The good thing is Tim went with him, Tim made him do a CT scan and they found out about it."
Since missing three games with a hip injury in mid-December, Teletovic averaged 6.4 points on 32.2 percent shooting -- including 30.4 percent from 3-point range in 21 games. He finished the season averaging 8.5 points and 4.9 rebounds in 40 games.
"On the basketball side," King said, "we will explore all of the options available to us."
The Nets are already without point guard Deron Williams, who has missed the past eight games because of a rib cartilage fracture. Williams will miss at least one more game. There is no timetable for his return, though he has been getting up shots recently.