The Nets, who entered the season with a $190 million payroll and high expectations, have not met them thus far.
"We haven't played well," King said. "We haven't played up to our potential; injuries aside we've gotta play better. It's on all of us as an organization to do a better job."
Point guard Deron Williams (11 games) and small forward Paul Pierce (five games) have also missed significant time due to injury. Still, the Nets find themselves just two games back in the Atlantic Division standings.
"It's crazy," King said. "You can keep saying you're only two games back and keep being two games back and at the end of the year finish two games back. We need to start playing better."
King said the biggest thing the Nets need to improve on is rebounding. They rank 28th in the league in that category.
Shooting guard Joe Johnson said he was "devastated" when he heard the news.
"It just seems it's almost like we can't a break," Johnson said. "There's always something."
Johnson expects the Nets to have to play a more "uptempo" style with Lopez out.
"I just hate it for the big fella because I know he worked so hard and prepared himself for this season," Johnson said.
Mike Mazzeo is a regular contributor to ESPNNewYork.com.