Currently, Yankees closer Mariano Rivera wears number 42. Mariano is the last day to day player to wear that number in Major League baseball, and upon his retirement or change of number, will be the last to ever wear the number 42.
Mariano Rivera is the current player and will be the last player on the Yankees to wear number 42. The number was retired throughout baseball in honor of Jackie Robinson. The players who were wearing that number when it was retired were allowed to keep it.
Prior to 2010, running back Willie Parker was the last Steelers player to wear #39. He wore it from 2004-2009.
Outfielder Steve Henderson in 1988.