Chico Harlan at the Washington Post wrote that the “Nationals’ roster seems unusually well-defined” this morning, but apparently it’s getting a lot, well, less defined this afternoon.

According to Bill Ladson of MLB.com, the Nats agreed to terms with Livan Hernandez on a Minor League deal today.

This is doubly good news for the Mets: First, it means the Mets will not acquire Livan Hernandez at any time in the foreseeable future. Not that the move had been rumored, but, well, it’s always good to have to certainty.

Second, it means there’s a good chance the Mets will face Livan Hernandez several times in 2010.

I don’t mean to discredit the 135 innings Livan scarfed down for the Mets in 2009, especially given how pitiful the Mets’ starting staff was at times last season, but Hernandez’s unique ability to stay healthy enough to make 30+ starts a year has now been entirely mitigated by his inability to retire Major League hitters in any consistent fashion.

Hernandez finished dead last among qualifying pitchers in the Majors with a 76 ERA+ in 2009 after finishing second to last with a 71 ERA+ in 2008. I defy you to find someone who has been permitted to throw so many innings so poorly since Jose Lima.

No one will convince me that Hernandez can offer more to a team than Nelson Figueroa at this point, which is good, because I don’t think anyone’s trying. Even his once-lauded batting abilities have withered with time.