The Nets need a win Wednesday or a Washington Wizards loss in Boston against the Celtics to guarantee the fifth seed.
Brooklyn is stumbling a bit heading toward the postseason. The Nets have dropped three of their last four, including two at home. The most recent setback came Tuesday night at the Barclays Center against the New York Knicks, 109-98.
Marcus Thornton netted 24 points for the Nets, who couldn't get by the Knicks, despite the fact that leading scorer Carmelo Anthony wasn't in action due to a shoulder injury.
Mason Plumlee tallied 16 points with nine rebounds and Paul Pierce dropped in 13 in the setback.
Pierce's 3-pointer to open the game marked his 1,000th point of the season, which made him the sixth player in history to record 1,000 points in 15 straight seasons.
"We want guys to be healthy going into the playoffs," said Pierce. "One of our biggest strengths is our depth so it's important that the guys get healthy for us to try and make this run."
The Cavaliers have lost two straight and four of five.
On Saturday, Cleveland lost at home to the Boston Celtics, 111-99, to help the Celtics end a 13-game road losing streak.
"We have to do a better job of battling human nature and not allowing that to impact our effort," said Cavs center Spencer Hawes, who did not score after opening the game with a 3-pointer.
Kyrie Irving, Dion Waiters and Jarrett Jack all scored 15 points. Tristan Thompson netted 14 and Tyler Zeller managed 12 points, followed by 11 from Alonzo Gee and 10 out of Matthew Dellavedova.
Hawes also grabbed 10 boards.
The Nets have taken two of three against the Cavaliers this season, but Brooklyn has won six of the last seven meetings. The Nets are 4-2 in their last six at the Q.