Argentine media reports that Del Potro will miss this year's #NittoATPFinals after qualifying for the first time since 2013.
The two icons are scheduled for an appearance in Saudi Arabia in December, but recent events have put it into question.
The 8-time major champion arrived on Saturday to join forces with Grigor Dimitrov in Paris.
The Czech won five titles, reeled off two mammoth win streaks and claimed 47 victories in 2018.
The Dane revealed the diagnosis after her season ended on Thursday at the WTA Finals.
The Swiss scampers in style to win a gorgeous point against Filip Krajinovic.
Hall of Famer says it's a matter of time: Serena will win more majors.
