Porter Jr. was a key reason for the Portland Trail Blazers first round exit last season, hitting crucial shots and providing stingy defense.
The 23-year-old has dealt with back injuries since college and now waits to see if a third surgery is required to address the nerve issue.
The Nuggets have been vague about specifics of the injury and when Porter might be expected back. They have given him a timeline of a week to show improvements before considering other treatment options. Another back surgery is a possibility, sources said.
The Nuggets signed Porter to a five-year max contract in late September. A large portion of the contract – $145 million – is guaranteed.
In his nine games this season, Porter Jr. has put up 9.9 points on 36 percent shooting and 21 percent from three.