When he debuted in 1999, he became the first player from Stony Brook to reach the MLB. After a few years of splitting time between the major leagues and minor leagues, Nathan had a breakout season as a setup man for the Giants in 2003. That offseason, Nathan was traded to the Twins and became their closer. From 2004 to 2009, Nathan was considered one of the top closers in the major leagues, with four All-Star selections and a league-leading 246 saves. Nathan finished fourth in American League (AL) Cy Young voting in 2004 and fifth in 2006.