Tom Brady and Gisele Bundchen pay tribute to son Ben on his 14th birthday as former QB warns Rob Gronkowski to 'watch out' with teenager dreaming of emulating legendary tight end

Tom Brady has joked that former teammate Rob Gronkowski must 'watch out' as he paid tribute to his son Ben on the teenager's 14th birthday.

'Can you believe it? Fourteen years old already!' the legendary quarterback wrote on social media on Friday. 

'It seems like yesterday you were running around in your superhero cape, and now you’re definitely a superhero to me... we love you so much. You are a blessing to us all and we adore you!'

Alongside his words, Brady posted a selection of pictures of his second son. One showed the teenager in his football uniform.

Ben was wearing No 12 - the number his father wore during a remarkable career that brought seven Super Bowl rings and more than $500million in earnings.

But the teenager dreams of playing tight end and, on his son's birthday, Brady sent a warning to Gronkowski - alongside whom he won Super Bowl titles with the Patriots and Buccaneers. 

'You’ve grown so much, and not just in height (seriously, watch out @gronk),' he wrote. 

'You’ve grown in kindness, smarts, and all-around awesomeness. Your ability to make people laugh, your knack for solving problems, and your endless debating skills make you a force to be reckoned with.'

Brady ended his tribute with another joke, reminding his son: 'No, you can’t stay up until 3am playing video games now that you’re 14. Nice try tho (sic)'

Ben's mom, Gisele Bundchen, also posted her own tribute to their son. 'Happy birthday to the sweetest boy! You have the biggest heart and I feel so lucky I get to learn with you everyday,' she wrote. 

'Ps. One day your baby will stand as tall as you are. And you won’t be ready for it.'