The New York Timesexcellent pieceBill BelichickThe Wall Street Journalgood article
[T]he coach and owner exploded at each other over Mr. Nelson's refusal to fulfill his boss's wish to play an injured Mr. Nowitzki, according to Mavericks officials close to the team's owner.Isaac Chotiner
Mr. Nowitzki had suffered sprained ligaments in his left knee in the third game of the best-of-seven series, but, with the Mavericks trailing three games to one, was cleared by team doctors to play again. Mr. Cuban confronted Mr. Nelson in the coach's office and demanded the star forward return to the court, Mavericks officials say.
Mr. Nelson refused, insisting that playing the young German with the ligament injury would jeopardize his career. The coach also confided in friends that he had promised Mr. Nowitzki's parents, when the Mavericks signed the young man at age 19, that he would look after the seven-footer in Texas like a son.