Boston Red Sox -- White House Staffer BEARDS UP ... to Meet World Series Champs

The Boston Red Sox are all set to meet President Obama at the White House today ... and one W.H. staffer is so pumped, he THREW ON A BEARD in honor of his favorite team.

The man behind the whiskers is White House press secretary Jay Carney -- a well-known Red Sox superfan.

In fact, the day after the Sox won the series, he wore a Boston hat to start his daily briefing.

This morning, the White House's official twitter page posted a pic of Carney in full face warmer with the hashtag "GetBeard."