Irving was wearing a mask after fracturing a bone in his face prior to training camp, and according to ESPN's Rachel Nichols, the severity of the injury isn't yet known.
Kyrie was making his preseason debut, but he lasted only one minute before leaving.
Injuries have been a recurring problem for Irving throughout his NBA career. The six-time All-Star has only reached the 70-game barrier three times in his eight NBA seasons, and he missed 37 games in two years with the Boston Celtics.
When Irving is on the court, he's one of the most dynamic scoring guards in the NBA. Uncle Drew has averaged at least 23.8 points per game and shot over 40.0 percent from three-point range in each of the past three seasons.
The Nets have a lot invested in Irving leading them this season, especially with fellow summer addition Kevin Durant unavailable until 2020-21 while rehabbing his Achilles.
Head coach Kenny Atkinson has a good roster to work with, led by Caris LeVert, Joe Harris, Garrett Temple, Spencer Dinwiddie and Taurean Prince. But Irving is the only go-to scorer who can be relied upon to dominate the ball in crunch time.
As long as Irving's latest injury doesn't linger into the regular season, the Nets should still be able to compete for a playoff spot in the Eastern Conference.