The Blazers initially signed the 2016 lottery pick to a 10-day contract March 8. He hasn't logged any playing time since arriving in Portland.
Papagiannis spent the first two years of his career with the Sacramento Kings.
Viewed as a flier at the time, Papagiannis was never able to consistently crack the Kings' rotation despite packing plenty of intrigue at 7'1'' and 240 pounds.
In 38 total appearances with Sacramento, the Greek big man registered 4.2 points, 3.2 rebounds and 0.6 blocks per game.
The Blazers are replete with frontcourt depth in the form of Jusuf Nurkic, Ed Davis, Zach Collins and Meyers Leonard, so a series of injuries will likely need to occur in order for Papagiannis to see the floor anytime soon.