He also played for the New England Patriots and Jacksonville Jaguars in the National Football League (NFL).

Gaffney was picked by the Pittsburgh Pirates in the 24th round of the 2012 MLB Draft and went on to play two seasons of minor league baseball.

Gaffney attended Cathedral Catholic High School in San Diego.

[1] During his high school football career, he rushed for 5,547 yards with 99 total touchdowns.

[2] As a true freshman in 2009, Gaffney played in 12 games, rushing for 87 yards on 22 carries with a touchdown.

[8] While he was originally slated to compete for the third running back spot on the roster with second-year runner Kenjon Barner, on July 26, 2014, Gaffney went down with a torn lateral meniscus in his left knee during training camp.

Gaffney won Super Bowl XLIX with the Patriots after they defeated the defending champion Seattle Seahawks 28–24.

[17][18] On November 10, 2016, Gaffney was waived by the Patriots and was re-signed to the practice squad two days later.

Gaffney returned to baseball for the 2018 season after moving on from the NFL, joining the Pittsburgh Pirates' minor league affiliate Bradenton Marauders.

In 89 games between the Pirates' High-A Bradenton and Double-A Altoona affiliates, he batted .244 with six homers and 36 RBIs.