The NFL legend is a minority owner of the Blues who were playing the biggest match of their season so far as they faced Newcastle United in the FA Cup.
Unfortunately for Brady, Birmingham's clash with the Premier League side fell on the same weekend as the Super Bowl with the Kansas City Chiefs facing the Philadelphia Eagles in New Orleans, Louisiana.
Speaking on the BBC, Shearer joked: "I can't believe Tom Brady has chosen the Super Bowl instead of the FA Cup.
"It's a bit rude, isn't it?"
Shearer's comment was followed by a chuckle with Gary Lineker replying: "I know.
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"On a beautiful evening like this too."
The Newcastle legend then added: "Especially to see one of the biggest clubs in the world as well," to which fellow pundit Curtis Davies sarcastically replied: "Birmingham?"
Brady's failure to attend the clash at St Andrews is down to his lucrative commitment to a major broadcaster in the US.
The seven-time Super Bowl winner is working as a colour commentator for Fox Sports.
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The network shelled out a mammoth $375million to tie him down for a decade, with the battle for the Vince Lombardi Trophy, unsurprisingly, the biggest event on their calendar.
That said, Brady missed a heck of a contest at St Andrews.
Brady's Birmingham City took the lead inside one minute when Ethan Laird gave the Blues the lead.
Newcastle then scored a controversial equaliser when Joe Willock's goal was adjudged to have gone over the line despite Bailey Peacock-Farrell making what appeared to be the save of a lifetime.
But with no goal-line technology, the goal stood.
Callum Wilson then put Newcastle ahead, before Tomoki Iwata drew the game level just before half time.
However with the contest looking likely to head for extra-time, Willock struck again to secure a 3-2 win for Newcastle and earn them a spot in the hat for the fifth round.
While it was a night that didn't go to plan for Birmingham, they have their sights firmly set on promotion to the Championship this term.
Match Stats
The Blues currently sit four points clear at the top of League One having played two games fewer than the sides below them in the table.