New Red Sox slugger J.D. Martinez celebrated his 19th birthday at Fenway Park

Arguably the biggest free agent on the market found a home on Monday, as J.D. Martinez agreed to a five-year deal with the Red Sox. Just what made the man known as Just Dingers choose Boston? The $110 million probably has something to do with it -- but little did we know, Martinez and Fenway Park go way back:

Martinez's sister posted the above photo on Monday evening, showing she and Martinez taking in a game at Fenway Park for his 19th birthday. Just which game was it, you ask? It was a showdown between the Yankees and Red Sox on Aug. 21, 2006 -- New York won, 2-1, to complete a five-game sweep that put it solidly in first in the AL East. (In other, no less important news, Wily Mo Pena homered.)
But that was just the beginning of Martinez's Fenway experience. He also met a few upstanding members of Red Sox Nation, who did not disappoint: 

No wonder he signed on the dotted line.