The Pelicans specifically noted that Williamson suffered a fractured left ring finger and that a treatment plan and timetable for his return will be determined after further evaluation.
New Orleans, which is 11th in the Western Conference at 30-36, has just six regular-season games remaining. The teams seeded seventh through 10th in each conference will compete in a postseason play-in tournament, and the Pels are currently 1.5 games behind the 10th-place San Antonio Spurs.
Per ESPN's Andrew Lopez, Pelicans Executive Vice President of Basketball Operations David Griffin said the injury was "avoidable" and that Zion has not been officiated properly this season. Griffin added that the team sent film to the NBA to show how often Williamson has been hit under the rim.
Williamson has been relatively healthy this season, although he missed a Jan. 13 game against the Los Angeles Clippers because of the league's health and safety protocols.
"He had inconclusive [COVID-19 test] results and the timing became a factor," Pels head coach Stan Van Gundy said (h/t ESPN's Adrian Wojnarowski).
"He's not with us here at the game tonight. He's back in his hotel room. We'll know more as further results come back."
Testing ended up being negative, and Williamson returned for the team's next game.
Williamson has been a force this season, averaging 27.0 points, 7.2 rebounds and 3.7 assists. He was also named an All-Star for the first time in his NBA career.
With Zion also out, the Pelicans will turn to the likes of Lonzo Ball and Eric Bledsoe as their top contributors, along with big men Willy Hernangomez and Jaxson Hayes.