If the San Francisco 49ers have a big lead in Super Bowl LIV on Sunday, their coaching staff are unlikely to let minds drift to thoughts of confetti, parades and rings.

They may have been forgiven for doing so three years ago when the Atlanta Falcons led the New England Patriots 28-3 late in the third quarter of Super Bowl LI.

Lady Gaga, the half-time act that year, had long finished singing. But it turned out the fat lady had not.

Back came the Patriots, Kyle Shanahan's offense unable to add further points to their total, and Tom Brady perhaps cementing his legacy as the G.O.A.T by inspiring a 34-28 overtime win that stunned the Falcons.

Shanahan has since left Atlanta, taking the Niners' head-coaching post shortly after, but he admitted this week that Super Bowl scars remain.

The same is true for the staff he brought with him. Those aiming to banish the demons of Houston. Of '28-3'.

"I'm not gonna lie; you still think about it quite a bit," the Niners' passing-game coordinator Mike LaFleur told Omnisport.

Shanahan said the only play he would have called differently in that second half was a second-and-11 pass play that resulted in Matt Ryan being sacked and pushed out of field-goal range.

Yet the Patriots' comeback was a brutal reminder of how even sizeable advantages can be eroded in the NFL.

At Super Bowl LIV, the Niners face a Kansas City Chiefs team that have already overturned 24 and 10-point leads this postseason.

Those who know Shanahan best believe a return to the Super Bowl will not suddenly trigger post-traumatic stress because '28-3' has always been with him ever since it happened.

San Francisco's run-game coordinator Mike McDaniel, who, like LaFleur, worked with Shanahan in Atlanta and at the Cleveland Browns, told Omnisport: "It's just the final game of the season, the stakes are incredibly high but I wouldn’t say that it would venture into Kyle's head any more than any other lesson.

"You'll never forget. Once you lose a Super Bowl like that, you just never feel comfortable with a lead, but that's been every single game since that we've been burying that weight.

"That's a lesson that you'll always be mindful of and you'll lose leads in the future but you'll do your best and better understand and think through how to handle situations - like all coaches that are able to have sustained success like Kyle."

LaFleur is adamant that Shanahan remained an aggressive playcaller in Houston, but he also recognises that, should the Niners find themselves in a similarly dominant position against the Chiefs, no one will be getting complacent.

Not with Patrick Mahomes on the other sideline. Not with '28-3' in their minds.

"I just know up in the box on Sundays, I don't care what the score is," LaFleur added.

"We had numerous times this year where we had big leads and you don't feel comfortable.