The Barcelona star's brother posted an image of the bodyart on Twitter, which was inked just three days prior to Argentina's World Cup qualifier with Venezuela
The body art, which depicts a small pair of hands and the name Thiago in simple black ink, was photographed by the Barcelona star's brother Matias before being uploaded to Twitter.
Matias had revealed earlier this week the pair had planned to get new tattoos, and he released pictures of them both on social media networks on Wednesday evening.
Messi is currently on international duty with Argentina, and is set to captain the side in Friday's World Cup qualifier with Venezuela.
Regardless of the touching tribute to his young son, the 25-year-old has likely made national boss Alejandro Sabella a little nervous prior to the match, given that the rather large tattoo is periously close to the most magical of left feet.