Philadelphia 76ers big man Al Horford's sister took a shot at Sixers head coach Brett Brown on Wednesday.

Horford played for the Boston Celtics for three seasons before signing with the Sixers last summer. Horford's sister is still popular with Celtics fans on Twitter, which made her tweet bashing Brown even more noteworthy.

Brett Brown is on the hot seat with the Sixers. If the team doesn't play well in the 2020 postseason, most pundits believe Philadelphia general manager Elton Brand will fire Brown.

Even though the Sixers are without All-Star point-forward Ben Simmons, Brown may still be on the hot seat since the team underwhelmed even when the former No. 1 overall pick and Rookie of the Year was in the lineup. Simmons is expected to miss the 2020 playoffs after undergoing knee surgery.

Horford's first season with the Sixers has been a nightmare. After initially starting alongside Joel Embiid during the 2019-20 season, Horford's fit with Embiid has been a disaster, with his presence making the floor spacing with Embiid and Ben Simmons even worse than it was last season despite being a career 36 percent shooter from the outside.

Fans have resorted to booing the multi-million dollar signing, forcing Brown to get creative by moving him to the bench as a sixth man for the first time ever in his whole career. Horford averaged 11.9 points, 6.8 rebounds and 4.0 assists during the regular season.

It will be interesting to see whether Brown or Horford (or possibly both) are gone from Philadelphia after this season.