The Los Angeles Lakers previously said that the guard, who is the oldest player in the NBA, would not play again this season because of a nerve problem, but he featured for 19 minutes in yesterday's 117-107 loss.
The Wizards' top scorer told reporters: "It didn't look like he missed a beat to me. That's how talented he is.
"No matter how old Steve Nash is, man, whenever he runs that pick-and-roll, he's efficient and one of the best at passing and getting his shot.
"A lot of people are writing him off, but when he's healthy, he's still one of the greatest all-time. So you've got to respect a two-time MVP in this league."
The 40-year-old scored five points in his 11th appearance of the season.