share-square-1080221 HOUSTON -- What’s in a number? Well, quite a lot when they’re worn by baseball players. The wearing of a particular jersey number is something most players take very seriously, while some are just glad to have any kind of number below their name on a big league uniform. The Astros have 10 retired jersey numbers, including Jackie Robinson’s No. 42 that was retired around baseball prior to the 1997 season. The last number retired by the Astros was the No. 7 worn by Hall of Famer Craig Biggio, who actually broke into the Major Leagues wearing No. 4. And did you know 14 players wore No. 24 after Jimmy Wynn before the Astros decided to retire it in 2005?