Tim Tebow - with his trademark biblical references painted underneath his eyes - and his mother Pam will star in the controversial anti-abortion ad
By Haydn Parry
BBC Sports News, at the Super Bowl in Miami
Tim Tebow is used to making headlines in the States. As a college football star quarterback with the Florida Gators, he will soon be stepping up into the National Football League. But he is making news right now for his forthcoming appearance in a controversial commercial set to run during Sunday night's televised coverage of Super Bowl XLIV.
A conservative Christian group, Focus on the Family, have paid for a 30-second slot during CBS' coverage of the game.
The advert will feature the story of Tim Tebow's mother, Pam.
As a Christian missionary in the Far East 23 years ago, she fell very ill while pregnant and was advised by doctors to have an abortion. She ignored that medical advice and gave birth to a fifth child, her son Tim, the future football star.
Tim Tebow, who is known to display biblical line references on his playing uniform, has not shied away from the controversy stirred up by the ad: "I know some people won't agree with it but I think they can at least respect that I stand up for what I believe... my mom was a very courageous woman."
Traditionally, the commercials broadcast during the Super Bowl have steered well clear of any polarising issues, tending more to focus on humour and light-hearted whimsy, and so a pro-life "advocacy ad" represents a major change.
Women's rights groups have been calling on CBS to withdraw the ad.
Terry O'Neill, President of the National Organisation for Women (Now), told the BBC she thinks the Tebow ad is totally inappropriate.
"We can celebrate the ability of people like Pam Tebow to make her own healthcare decisions, to make decisions about her family and her future. And we do celebrate that. But we would also celebrate the same situation, a different woman with a risky pregnancy, if she decided to terminate that pregnancy - we would celebrate her ability to make her decision for her healthcare and her future.
"This is an ad with a not-so-subtle implied message that women who would make a different decision, who would decide to end a pregnancy, they should be ashamed," she said.
CBS insist the script of the commercial has been approved and is "appropriate for air".
A 30-second ad during the Super Bowl this year costs between $2.5m and $2.8m but, for that money, the commercial is expected to reach a watching audience in the US of around 100 million, a third of the country's population.
Dave Kline is one of only four men to have covered all 44 Super Bowls and remembers the early days when the networks struggled to sell advert slots.
He is uneasy about this change of stance on advocacy ads during the big game.
"I'm not sure the time has come but there are people who do think the time has come. If they want to put the 'nearly-sainted' Tim Tebow on air, then there will continue to be an escalation, with more and more of these ads, pro-abortion, anti-abortion and anything else they can think of," Mr Kline said.
While very little detail of what exactly is said in the ad is known, it is understood that the words "abortion" and "pro-life" do not feature.
Gary Schneeberger, a vice-president and spokesman for Focus on the Family has not given any more clues in recent interviews but has noted the anticipation the media interest has built up.
"There has been a lot of speculation about what it is, but we've never said exactly what the ad is about, precisely because we want the impact of the slot to be on Super Bowl Sunday.
"Most of the folks having ads in the Super Bowl are trying to sell you something. We're not trying to sell a car, a soft drink or a web domain name. We're not selling anything - we're celebrating families. It's an opportunity for us to reach a large audience with the many resources we have and that's the heart of what we do as a Christian ministry," Mr Schneeberger said.
The Tebow ad still looks likely to run this Sunday night - the reaction of Americans watching will determine if more of these advocacy ads are let near the huge Super Bowl audience in future.