The Bullets probably will trade forward Len Robinson for either guard Tom Henderson of the Atlanta Hawks or forward Bob Dandridge of the Milwaukee Bucks, according to NBA sources.

Bullets officials would not comment on the possible trade.

The ideal is supposed to be made within a week well before the Feb. 1 trading deadline.

Robinson, a starter all season who has fallen from favor with coach Dick Motta, was demoted tonight and replaced by Kevin Grevey. Robinson, who has a 16.3 scoring average, said he wants to be traded.

Henderson is particularly appealing to the Bullets and could be the answer to their ball-handling woes. He is a good passer, and Motta likes him.

Kf tte Bullets were to acquire Henderson, rookie Larry Wright, who replaced Dave Bing in the starting lineup, probably will become the third guard.

While playing for the lowly Hawks, Henderson has averaged 8.5 assists a game, putting him second in the NBA in that department.

Atlanta has an abundance of guards but is weak up front. Milwaukee also needs a power forward.

Presently the Bucks are starting two small forwards in Dandridge and Junior Bridgeman Dandridge is 16th in the NBA in scoring with a 20.7 average.