Joseph "Jack" Buren Cassel II (born August 8, 1980) is an American former Major League Baseball pitcher for the San Diego Padres and Houston Astros organizations.

In addition, he is a co-founder and board member of Players for the Planet, a non-profit organization that utilizes professional athletes to promote and inspire environmental awareness.

Cassel made his Major League Baseball debut with the San Diego Padres on August 10, 2007 in Cincinnati against the Reds.

On August 31, Cassel returned to the Major League club and made his first MLB start against the Los Angeles Dodgers.

He signed with the Houston Astros shortly afterwards and competed for a spot in the starting rotation in spring training, but began the year in the minor leagues.

Cassel attended Loyola Marymount University after graduating from John F. Kennedy High School in 1998, where he received All-State Honors in baseball.

Jack's younger brother, Matt Cassel, is a former journeyman American football quarterback who notably played with the New England Patriots and Kansas City Chiefs.

His other younger brother, Justin Cassel, was a minor league baseball player in the farm system of the Chicago White Sox and won a silver medal for Team USA.

[1] Several athletes including Jay Bruce, Ryan Braun, Matt Cassel, Curtis Granderson are on board to spread the awareness.