WALTHAM — In a move that will add depth to their suddenly shrunken roster, the Celtics are expected to sign Rio Grande Valley Vipers small forward Chris Johnson to a 10-day contract on Friday.
Johnson has been playing for the Rockets’ affiliate in the NBA Development League, where he is averaging 19.4 points and 6.8 rebounds in 20 games this season.
“Chris has been playing very well. We need a wing player, we need someone who can shoot the ball, so Chris will add some depth to our team for now,” president of basketball operations Danny Ainge said before practice Thursday.
Johnson played in eight games with the Memphis Grizzlies last season on a pair of 10-day contracts. Full story for BostonGlobe.com subscribers.