Chelsea were blocked by the Premier League from agreeing a new shirt sponsor deal.
The Blues are now in advanced talks with Stake.com about a 40m-a-year agreement.
However, the Daily Mail says they only turned to the betting firm after being blocked from agreeing terms with Paramount Plus.
Paramount Plus are a US streaming service which also sponsor Inter Milan's shirts.
The Premier League refused Chelsea permission to sign with Paramount as it would have upset UK broadcasters.
The Stake.com agreement is expected to be short-term with a betting ban for shirt sponsors to be introduced from 2025.