In early April, as the Rutgers president, Robert L. Barchi, was working to defuse a coaching abuse scandal, he named Gregory S. Jackson, a university administrator, to be his chief of staff.

Jackson, though, was already facing his own legal problems. About three months earlier, Jackson was sued by four longtime employees in the university’s career services office, all in their late 50s and early 60s. They said that he had engaged in a “campaign of discriminatory actions” against them because of their age, ostracizing them and ultimately forcing their retirement. Barchi was aware of the lawsuit when he promoted Jackson, according to Rutgers officials.

Knowledge of the lawsuit comes as Barchi is struggling to steer the university out of a public-relations crisis that has already upended the athletic department, drawn the ire of elected officials across New Jersey and threatened to snarl ambitious plans pushed by Gov. Chris Christie to restructure the university.

Jackson is the third Rutgers official to face public criticism for discriminatory or abusive behavior in recent months. Mike Rice, the former men’s basketball coach, was fired in April for hurling slurs and epithets at his players; Julie Hermann, the new athletic director, has been under fire amid allegations of misconduct at her previous jobs.