Super Bowl XLVII would be the ultimate family gathering for the Harbaughs in New Orleans this weekend – if one team did not have to lose.

John Harbaugh will coach his Baltimore Ravens against younger brother Jim and his San Francisco 49ers, with parents Jack and Jackie, and sister Joani trying to keep their emotions in check from the stands.

"Anybody who has a brother, especially one that's close in age, gets it," John said. "You just grow up fighting for everything. You fight for the extra hotdog. You fight for girls. You fight for everything. But we both want a victory this week."

Only one year separates the brothers in age, but John has been Ravens coach since 2008 and has reached the play-offs five times.

Jim is in his second season with the 49ers, and although he also has a 100% record of reaching the post-season himself, he is happy to defer to his elder sibling. He said: "He's a great coach. I'm half the coach that he is but I'm trying."

Told about the remarks, John said: "He's just trying to soften me up."

The brothers grew up with football in their blood thanks to father Jack, a coach at high school and college level.

During endless games in the back yard, nobody imagined it would one day lead to this.

"We had fights, we had imaginary games more often in the back yard," John said. "We were never coaches. We were the quarterback and receiver, we were the stars.

"The truth is it's not going to be about the coaches on Sunday. It's about the guys playing the game."