Following the second defeat Friday, Nets guard James Harden commented on the team's defensive effort.
"Our problem isn't offense," Harden told reporters. "Defensively, we have to be more engaged."
The Cavs shot 51.7 percent from the field and outrebounded the Nets 50-29 in Friday's 125-113 win.
Two days earlier, the Cavs won 147-135 in double overtime after shooting 51.4 percent from the field, with Cavs guard Collin Sexton scoring a game-high 42 points.
Following Friday's game, Nets head coach Steve Nash also spoke about his team's defense.
"We're not a defensive roster. We have to take more pride and we have to win more 50-50s, contest more shots, fight, scrap, claw," Nash told reporters. "And that's what I think is missing as much as anything schematic that we're breaking down."
Expectations are sky-high for the Nets after their acquisition of James Harden. Between him, Kyrie Irving and Kevin Durant, they have three NBA championships, a pair of NBA MVP awards and 24 All-Star Game appearances combined.
Irving recognized that fact following the latest loss:
Irving, Durant and Harden have played only one game together (Wednesday's loss), so this new roster hasn't had much time to gel.
Nets big man DeAndre Jordan noted it will take time for the roster to reach its peak form.
"Rome wasn't built in a day," Jordan told reporters. "Championship teams weren't built in a day."
Irving noted that it's a long season, but he said the two Cavs losses were "humbling."
The Nets are now 9-8 following the pair of defeats to Cleveland. They'll look to bounce back when they return home to face the Miami Heat for a pair of games on Saturday and Monday.