The Super Bowl has been dubbed the 'Har-Bowl' with sibling head coaches Jim and John Harbaugh going head to head but there is another family rivalry on the line - father versus son.
San Francisco 49ers head coach Jim's eldest son Jay is a coaching intern with Sunday's rivals, the Baltimore Ravens, adding an extra family twist to the occasion.
Jay Harbaugh's role has not been referred to by either his father or uncle during the intense media build-up to the game but it was revealed by grandfather Jack at a press conference on Wednesday.
The press conference was held for Jack and his wife Jackie to discuss their feelings as parents with two sons competing as coaches for American football's top prize.
"One story I want to mention is Jay Harbaugh, how many know who Jay Harbaugh is? Anybody know Jay Harbaugh?" asked Jack.
"Jay Harbaugh is Jim's oldest son and he's on the coaching staff for the Ravens. He's doing the grunt work there as the assistant strength coach.
"It's kind of an interesting story. He does video and works in the weight room ... so you've got father and son competing on Sunday night as well."
Jay Harbaugh is not listed among the Ravens coaching staff but a team official confirmed he is a "coaching intern" with the club.