On April 18, 1971, he was traded to the defending NFC champion Dallas Cowboys in exchange for wide receiver Dennis Homan.
On July 31, 1972, he was traded to the Oakland Raiders in exchange for a fourth round draft choice (#97-Ken Hutcherson).
[3] In the 1972 preseason, Richardson became expendable with the play shown by rookie wide receivers Cliff Branch and Mike Siani.
[4] On September 11, 1972, he was traded to the Cleveland Browns in exchange for a fourth round draft choice (#93-Morris Bradshaw).
[5] During his three seasons with the Cleveland Browns, he was mainly used as a reserve player, making a total of 22 receptions for 448 yards and 3 touchdowns.