Roman Abramovich was prompted to put the club up for sale after mounting pressure on him over potential ties to Russian President Vladimir Putin.
The sale has been accelerated after Abramovich was sanctioned by the UK government, freezing his assets.
The Ricketts family are said to be leading a group of investors and will make an offer before Friday’s deadline.
“The Ricketts family, owners of the Chicago Cubs, can confirm they will be leading an investment group that will make a formal bid for Chelsea Football Club this Friday,” they confirmed in a statement.
“As long-time operators of an iconic professional sports team, the Ricketts Family and their partners understand the importance of investing for success on the pitch, while respecting the traditions of the club, the fans and the community.
“We look forward to sharing further details of our plans in due course.”