Al Horford logged just three points on 1-of-8 shooting on Friday night as the Boston Celtics lost to Jimmy Butler and the Miami Heat, 111-103, in Game 6 of the Eastern Conference Finals. It was a disappointing performance from the Celtics center and apparently, there could possibly be one major reason behind his lackluster showing.

Horford was playing with a heavy heart on Friday night. According to Enrico Rojas of ESPN, the Celtics big man lost his grandfather on Thursday. Horford soldiered on and decided to be there for his team the following day.

Translated via Google Translate:

José Reynoso, father of my friend and colleague Arelis Reynoso, passed away this morning and grandfather of the star NBA player Al Horford.

He was 81 years old. He will be buried on Saturday in Puerto Plata, Dominican Republic.

Apparently, Horford was very close to his grandfather. The Celtics star must have taken his death pretty hard. Horford's sister, Anna, also confirmed the news via Twitter as she shed some light on Al's relationship with Jose:

Despite this tragedy, I'm pretty sure that Horford is not going to make any excuses about his performance in Game 6. For what it's worth, he made up for his lack of scoring with nine rebounds and five assists in 33 minutes of action. Be that as it may, the Celtics will need more from him on Sunday as they face the Heat in the final game of this series.

Our thoughts and prayers go out to Al and the rest of the Horford family.