Dallas Mavericks center Chris Kaman is out indefinitely after suffering a concussion during a hard fall in practice on Monday.
Kaman is dealing with headaches and dizziness as a result of the collision with teammates, the Fort Worth Star-Telegram reported.
He missed Tuesday night's 106-104 loss to Portland and could be out for all four games in the Mavericks' road trip.
"I landed on my head from about three feet in the air," Kaman told the Star-Telegram. "And it hurt and I was dizzy a little bit. And then my vision was a little blurry for a little bit, then it slowly went away. And I've been having a headache for the last two days, and my neck is killing me."'
NBA policy regarding head injuries dictates that Kaman undergo testing before he can return.
"They just want me to take it easy and make sure that everything's good," Kaman said. "I had the test and everything, and I didn't pass that test. I'll try again and see how that goes."
Kaman is averaging 12.4 points and 6.2 rebounds per game this season.
"He'll be back when his symptoms abate; we don't know a timetable for it," coach Rick Carlisle said. "I don't think it's that serious, but these things, you've got to be very careful with. But this is a hit for us. Chris has played very well for us this year."