Arizona has a pitcher named Tony Peña. Kansas City has a shortstop named Tony Peña Jr. Needless to say, they aren't related. The Arizona Peña's real first name is Ramon while the Kansas City Peña's first name is Tony. Kansas City acquired their Peña from Atlanta, which still has its own Peña in catcher Brayan.
Arizona also has a Chris Young who is an outfielder, as opposed to San Diego's Chris Young who is a pitcher. Arizona has Christopher Brandon Young and San Diego has Christopher Ryan Young. I'm sure others can give you pointers on how to distinguish between the two.
The Chicago White Sox feature a player who went to my high school (John F. Kennedy High of Granada Hills, CA), Jon Garland, and a player who was born in the same hospital as me (Holy Cross Hospital, now called Providence Holy Cross, in Mission Hills, CA) in Bobby Jenks. I believe that fact is of even more limited interest than others I will be coming up with.
Detroit has pitcher Chad Durbin on the roster. Arizona has J.D. Durbin on the roster. They aren't related. And they don't seem to be related to the other Durbin who played in the majors Blaine Alphonsus "Kid" Durbin.
Bruce Chen made the Opening Day Roster for Texas. The Rangers are Chen's ninth different team in 10 major league season, and the first time he has played for a team in the West division of either league.