So far he's been out of the Eastern Conference Semifinals from what seems to be complications following the procedure.
He says he's been in and out of the hospital trying to get a very painful headache under control, but Deng is communicating with the team and fans sending tweets.
Last night he sent a picture from his hospital bed with the message: "So proud of my team, man this bed might be good luck afterall."
Several days ago he posted a tweet saying, "As a result of the spinal tap I suffered the worst headache I've ever experienced and been the weakest I've ever felt."
So what happened?
He underwent the spinal tap also called a lumbar puncture last Wednesday, after doctors were concerned he might have viral meningitis.
The results were negative.
Here's what the procedure involves.
A needle is carefully inserted into the spinal canal low in the back.
Cerebrospinal fluid can be collected and analyzed to look for many things including infection or bacteria.
Headaches from the procedure are thought to occur when some of that fluid leaks out.
For most people the pain goes away in 24 hours. But for some, the headache can persist.
UIC neurologist Octavia Kincaid says it's more likely to cause problems in younger patients, and those with less body fat.
"So you would think in a situation like our basketball player, young man with lots of lean muscle actually has a higher risk statistically for developing this complication than the average hospitalized patient would," said Kincaid.
For those headache cases that are more complicated, lasting more than a couple days, there are treatments to help speed the recovery.