Messi on Instagram. Thiago pic.twitter.com/H4fftjgBZo
— Leo Messi (@messi10stats) 17 de outubro de 2017
The two boys attended a training session organised by Barcelona, after which Messi posted the picture of them messing around on the edge of a group of other kids.
He captioned up the image: 'Annoying the little brother' followed by laughing emojis.
Thiago, four, can be seen pulling a funny face, while Mateo, one, seems a tad confused about what is going on.
Two stars for the future? Only time will tell.