The Argentine posted a video on social media of himself and his teammates celebrating their Copa America triumph.
However, the clip showed the squad singing a racist and derogatory chant about the nationalities and ethnicities of the France team members.
He has since circulated a message of apology around the Chelsea squad, per The Telegraph.
In their statement confirming the opening of an investigation, Chelsea said: “Chelsea Football Club finds all forms of discriminatory behaviour completely unacceptable. We are proud to be a diverse, inclusive club where people from all cultures, communities and identities feel welcome.
“We acknowledge and appreciate our player’s public apology and will use this as an opportunity to educate. The club has instigated an internal disciplinary procedure.”
FIFA has also responded to the video, stating: “Fifa is aware of a video circulating on social media and the incident is being looked into. Fifa strongly condemns any form of discrimination by anyone including players, fans and officials.”