Mariekson "Didi" Gregorius is apparently facing disciplinary action from the league for using a false identity, mlbtraderumors reports.
The article states that Gregorius' real name is in fact Jan Janssen. Oddly enough, his birth date of February 18, 1990 was apparently not falsified. The website posits that Janssen wanted to use a different name to get national recognition and wonders why he didn't just legally change his name, which would have made this whole mess go away. As it stands, Janssen will likely be suspended for 20 games and then will plummet down prospect listings because his real name is just kind of lame and no one really wants to see some guy named "Janssen" succeed.
The article can be found here.