It wasn't surprising that Danny White didn't stick around in 1989. He was going to be 37 years old and didn't play very much the season before. I think he may have retired even if Jerry didn't buy the team that year.
http://articles.latimes.com/1989-07-12/sports/sp-3656_1_cowboys-quarterback-danny-white
Cowboys Quarterback Danny White Retires
July 12, 1989|From Associated Press
IRVING, Tex. — Danny White, who spent 14 years in the NFL and was the Dallas Cowboys' starting quarterback for most of the 1980s, is retiring from the team today, a Cowboys spokesman said.
White scheduled an afternoon news conference to make the announcement, said Cowboys spokesman Dave Pelletier.
White joined Dallas in 1976 and became the team's starter after Roger Staubach retired in 1980. He led the team to the NFC East Division title in 1985 and led the league in touchdown percentage in 1986. With White as a starter, the Cowboys were 67-35.
White was plagued by injuries during the last three seasons, starting six games in 1986, nine in 1987 and none in 1988.
White's retirement comes five days after the team supplemented its quarterback corps by taking the University of Miami's Steve Walsh in the NFL supplemental draft.
The Cowboys drafted UCLA's Troy Aikman with the first pick of the regular draft and signed him to a six-year, $11-million contract.
"If they don't like me, it really doesn't matter," White said after Walsh was drafted. "I can't worry about the others. I made up my mind three months ago that nothing would surprise me."
But White worked out with the team's quarterbacks during a mini-camp the last two days.