Jason and Travis Kelce started the season talking about castrating bulls on their new podcast.

In a “mind-boggling” scenario, when Jason’s Philadelphia Eagles face Travis’ Kansas City Chiefs it will be the first time that brothers play against each other in the NFL’s championship game.

“You realise it could happen, I don’t think we ever thought it would though,” said Jason. “It’s got to be a lottery pick kind of probability.”

During Super Bowl week in Phoenix, their mother Donna has become arguably as famous as her sons, speaking to media from around the world about the ‘Kelce Bowl’.

And if the story was not already surreal enough, there could be another addition to the family this weekend.

Brothers reaching New Heights

Jason and Travis Kelce have both been in the NFL for at least 10 years now, winning one Super Bowl each.

They have each had numerous Pro Bowl selections, meaning they are the NFL’s best in their positions – centre and tight end, respectively.

But last summer they wanted to start a new venture, a podcast named New Heights after Cleveland Heights, the suburb where they grew up in Cleveland, Ohio.

On the first episode, Jason talks about getting very hands on with some cows he purchased last summer. That set the tone, and the topics have got more random while the brothers have got more relaxed.

New Heights is about football, family and fun, and it was one of the most popular podcasts in the US even before talk of the ‘Kelce Bowl’.

On last week’s episode Jason said he was “already over it” and they tried to play it down. But now they have fully embraced the media circus.

They are selling ‘Kelce Bowl’ merchandise and recorded the latest episode on ‘radio row’, where media broadcast around the clock during Super Bowl week.

Body slams and Bambi

At 35, Jason is two years older and in another episode Travis remembered how, when growing up, his big brother once body slammed him through a wooden floor in their living room.

To avoid getting caught immediately, they covered the hole with their couch. Boys will be boys.

Travis has been surprised that most of the questions during the numerous media opportunities this week have been about who won the most fights growing up.

“Jason won every fight but one – and that was the last one!” he said. “He stopped fighting me after that.”

That must have been when a sudden growth spurt meant Travis catch up with his older brother.

“It hit like lightning,” said Jason. “Overnight, he went from an uncoordinated Bambi to a full blown stallion. I was like ‘where did Seabiscuit come from?'”

At 6ft 5in, Travis is now two inches taller but Jason has a more stocky frame, weighing 134kg while Travis is 113kg. Jason’s main job is to block the opposition and he accepts Travis has always been the more gifted athlete.

Sadly, there will be no repeat of their boyhood battles on Sunday. They both play on offence so will never be on the field at the same time.

A Super Bowl baby?

The brothers credit their father Ed for giving them a love for sport – and their thick eyebrows. Ed paid for them to try several sports before settling on football, and they played on the same college team at the University of Cincinnati.

Since coming into the NFL they have been one-team men, and mother Donna has been their biggest fan.

During last season’s play-offs they played on the same day but hours apart so Donna watched the Eagles lose at Tampa Bay before flying 1,200 miles to Kansas City to see the Chiefs beat Pittsburgh.

The NFL tweeted progress reports on her journey and during the Chiefs’ post-match news conference she asked Travis about making the only touchdown pass of his career during that game.

But Travis accepts that, right now, Jason is her favourite, and Donna admits it too. That is because Jason and his wife Kylie have given her two grandchildren – and there is another on the way.

Kylie is 38 weeks pregnant and will be accompanied by her nurse at the game in Phoenix. If she goes into labour during the Super Bowl, the NFL’s medical staff have said they can deliver the baby at the State Farm Stadium.

And if so, Kylie has said that she and Jason have considered giving the baby the initials SB.

Thanksgiving bragging rights at stake

Super Bowl week begins with Opening Night, a fun media event where players are asked all sorts of questions.

Wearing a half-and-half jersey made from Chiefs and Eagles shirts, Donna joined her boys on stage and presented each with a box of homemade cookies.

She also answered questions about them by lifting paddles with their face on. Apparently younger brother Travis is the biggest mummy’s boy.

Donna has been a regular in the media centre all week, wearing a half-and-half denim jacket and chatting with as many reporters as she can. She also took part in Roger Goodell’s news conference, asking the NFL commissioner if he will go on her boys’ podcast. He is game.

Some fans have even started a petition for Donna to make the coin toss on Sunday, with 185,000 signatures at last glance.

And come full-time, Donna said she will only have the option of joining the winning son on the field as “the losers are immediately sent to their hotel. It’s like ‘go to your room’.”

She added: “I know both of them want this win desperately for bragging rights over the Thanksgiving table.”

‘For it all to align like it has, it’s mind-boggling’

There have been brothers in the Super Bowl before. John and Jim Harbaugh were rival head coaches at Super Bowl 47, while twins Devin and Jason McCourty were on the same team as the New England Patriots won Super Bowl 53, but brothers on rival teams is a first.

“Let’s just think how incredibly rare it is just to make it to the NFL [from high school],” said Jason Kelce.

“What are the chances that two guys get to the NFL [are signed], they realise their dream of playing in the NFL, then they become starters, All Pros and important pieces of their team, and then they end up playing each other in the Super Bowl?”

Travis, who should have more of an impact on the game as he is one of the NFL’s best receivers, added: “It’s wild – and kind of surreal. For it all to align like it has, it’s mind-boggling.

“It’s a special moment. It’s something we’ll remember for the rest of our lives. You guys talking a lot about me and my brother has been fun, we appreciate it, but at the same time I’m just trying to get a win for the Chiefs.”