The 19-year-old shared pictures of himself at the west London club’s Cobham training base and appears to be on the verge of rubberstamping his move from Atletico Paranaense.
The Brazil Under-20 international is rumoured to have cost around £4.5 million and could be joined by his Selecao team-mate Kenedy, who has also been heavily linked with a move to Jose Mourinho's side.
Although the Premier League champions have yet to announce the deal, Nathan was kitted out in full Chelsea garb and took to Instagram to thank the Blues for the chance to show off his skills in England.
“A dream is coming true! First of all I want to thank God for always lighting my way, my dad who always believed in my talent and was a real warrior while helping me to reach my goals, my family and friends who always supported me,” he wrote.
“And I am also thankful to Club Atletico Paranaense, which was part of this journey and where I played for 6 years of my career. Thank you Chelsea for trusting in me, I will do my best to support my team on reaching new achievements. WE ARE ALL BLUE.”