Also included in the deal was George, who has a one-year contract that features a no-trade clause.
George reportedly told the Mavericks before their game with Portland Wednesday that he would not consent to being a part of the deal.
When asked prior to the Portland game whether the deal to acquire Kidd would go through, Mavericks owner Mark Cuban told the Dallas Morning News: "No, I don't think so."
George started for the Mavericks against the Trail Blazers and Diop entered the game in a reserve role.
Kidd, a nine-time all-star, began his career with the Mavericks. He has 12 triple-doubles this season and 99 for his career.