Hideki Matsui, a Japanese player, played for a Japanese baseball team, then the New York Yankees for several years, then several more U.S. teams. On July 28, 2013, he signed a final one day contract with the Yankees, in order to retire as a Yankee.
How, if at all, did that affect the Yankees' 40 man roster? 1) Did they pick a day when they had only 39 men because of injuries or other reasons, making Matsui the 40th for one day? 2) Is there a "window" of say, 24 hours whereby the Yankees could temporarily have 41 men, as long as Matsui leaves within that window? 3) Or did the Yankees actually have to make a roster move to accommodate Matsui.