New York Yankees: 5 numbers that need to be un-retired

Yankees retire Paul O'Neill's No. 21 jersey

Why has there been a dizzying level of money and term in baseball free agency this year? - The Boston Globe

The Yankees Retire Paul O'Neill's Number 21 - The New York Times

Yankees Uniform Number Crunch May Force Coaches To Lose Number

The Yankees have retired so many numbers that they're down to just four available for new recruits: 38, 50, 57 and 69. : r/baseball

Here are the Yankees' 21 retired numbers Who belongs and who doesn't? Andy Pettitte, Jorge Posada, Bernie Williams, more

Yankees retired numbers and the baseball legends who wore them

Yankees Retired Numbers

2017 Yankees Review: Clint Frazier - Pinstripe Alley

Yankees' Anthony Volpe shines in 'dream' debut

The Athletic] The Yankees have asked MLB if they can stop issuing uniform numbers to their manager and coaches because they're running out of numbers that aren't retired : r/baseball

Names and Numbers: NY Yankees