Griffin has not played since suiting up Feb. 12 for the Detroit Pistons, who agreed to a buyout with the forward on March 5. The Nets officially announced his signing three days later.
He's sat out five games since the Nets acquired him and was listed with a "left knee - injury management" designation on the team's injury report. However, Griffin clarified to reporters that he wasn't hurt soon after reporting to the Nets.
"I'm not injured at all," Griffin said. "I just haven't played in three weeks, so I think it's smart to sort of ramp me up."
Griffin, a six-time All-Star and five-time All-NBA player, averaged 12.3 points and 5.2 rebounds in 20 games for the Pistons this season. He joins a 28-14 Nets team currently sitting a half-game behind the Philadelphia 76ers for first in the Eastern Conference.
He explained why he chose Brooklyn during a Bleacher Report AMA.
"They have a need for a 4-man," Griffin said. "I've always had a lot of respect for Steve Nash and all of the guys that they have. Sean Marks has done great job there. It was a tough decision and I wanted to be on a team that was contending."
The Nets will host the Wizards on Sunday at 7 p.m. ET in Barclays Center.