In 1990, Michael was again hired, this time as general manager of the Yankees. At a time when Steinbrenner was suspended from baseball operations by Commissioner Fay Vincent, Michael took advantage of his newfound managerial flexibility by rebuilding the Yankees farm system, in developing young talent rather than trading it away, as they had done in the 1980s with little success. During Michael's tenure as general manager, the Yankees drafted or signed such notable players as Mariano Rivera, Andy Pettitte, Derek Jeter, Jorge Posada (collectively known as the Core Four), and others. Further, he traded for Paul O'Neill. Michael also demonstrated patience with Bernie Williams, whom Yankees owner George Steinbrenner had wanted to trade when he struggled early in his career.