According to Adrian Wojnarowski of ESPN, Irving is expected to undergo an MRI on Sunday.
When asked if he was encouraged by the initial, Irving responded, per Yes Network's Michael Grady: "We'll see."
Brooklyn coach Kenny Atkinson declined to speculate on the nature of the injury after the game.
This is yet another setback for Irving, who missed significant time with a shoulder injury earlier this season. He also missed action with a hamstring injury and has played 70 or more games in a season just three times since he entered the league as the No. 1 overall pick in the 2011 NBA draft.
While the Nets remained in the playoff picture while he was previously sidelined, they likely need him healthy to compete with the best teams in the Eastern Conference come playoff time.
He is a six-time All-Star, two-time All-NBA selection and 2016 NBA champion who can break down opposing defenses off the bounce, hit from three-point range and facilitate when needed. He averaged 23.8 points, 6.9 assists, 5.0 rebounds and 1.5 steals per game last season for the Boston Celtics and has responded with a career-best 28.3 points per game in his first season with Brooklyn.
Fortunately for the Nets, they grew accustomed to playing without him earlier in the campaign.
Look for the combination of Caris LeVert and Spencer Dinwiddie to see more time in the backcourt until Irving is ready to return.