Referencing his brilliant free-kick goal against France in 1997, Carlos was keen to know if Robertson could do similar.
"Can you recreate my free-kick in a game?" he asked with a laughing emoji.
"First of all, imagine getting a question from Roberto Carlos - what a legend," a stunned Robertson replied.
"Thank you for your question and you're an absolute inspiration to me growing up and all of my generation.
"Secondly, I'd pay a lot of money to have your left foot. I'd love to be able to put in a free-kick like you did and I'm sure my team would as well.
"I'm not sure it's in my locker. I'll keep trying but, Roberto, I think I need to accept that it's never going to happen.