The power forward missed 19 games over a five-week period with the team while suffering from back spasms, but was able to make his comeback during last night's 105-101 win over the Philadelphia 76ers.
The 37-year-old told reporters: "I'm just glad I didn't mess anything up. The guys have been playing great without me.
"It just feels good to be able to move. I feel stronger than I have. I'm just glad I was strong enough to be out there."
Garnett has averaged 6.7 points in his 49 appearances for the Nets this season.