If Mariano Rivera's knee injury brings an end to his illustrious career, it also will mark the end of something else: the use of 42 as an MLB uniform number.
Forty-two was retired on an MLB-wide basis in honor of Jackie Robinson on April 15, 1997, but players who were already wearing the number at that time were allowed to continue doing so. Rivera is the final remaining player from that group. The last 42er other than him was Mo Vaughn, who wore 42 for the Mets in 2003. (And yes, for the past several years all MLB players have worn 42 on April 15 as a tribute to Robinson, but that's a one-shot deal, not a regular uni number assignment.)
With the 42 era possibly coming to a close, here are a few notes:
The grandfathered 42ers were allowed to keep wearing 42 when they moved to different teams, and at least two of them wore the number for three different clubs: Vaughn (Red Sox, Angels, Mets) and Butch Huskey (Mets, Mariners, Twins).
Huskey would have worn 42 for the Rockies as well, but team owner Jerry McMorris opted to keep the number out of circulation as a gesture of respect to Robinson. Another grandfathered 42er, Scott Karl, was forced to give up the number when he moved from the Brewers to Rockies.
Jose Lima, yet another grandfathered 42er, wore the number for the Astros and Tigers. He then wore different numbers while playing for the Royals and Dodgers. Upon joining the Mets in 2006, he asked to wear 42 and briefly had the number assigned to him in spring training, but the commissioner's office ruled that he had forfeited his grandfathered status when he'd worn non-42 numbers with his previous clubs. He ultimately wore 17 for the Mets.
Pitcher Mike Jackson actually wore 42 for five different teams (Giants, Reds, Mariners, Indians, Twins), but three of those came before the number had been retired from MLB.
The oddest 42er of the bunch was Marc Sagmoen, who was called up to the Rangers and assigned number 42 on April 15, 1997 -- the same date MLB announced that the number was being retired. He made his big league debut wearing 42 that night, then switched to 37 the next day.
You can see the last person to have worn 42 for each MLB team on this chart.
As for Rivera, if this really is the end of the line for him, he can feel good about having been the best in the business, even up to the advanced age of, naturally, 42.
Paul Lukas thinks Jose Lima got a raw deal on that uni number issue. If you liked this column, you'll probably like his daily Uni Watch web site, plus you can follow him on Twitter and Facebook. Want to learn about his Uni Watch Membership Program, be added to his mailing list so you'll always know when a new column has been posted, or just ask him a question? Contact him here.