Despite being heavily linked with re-signing the Bournemouth defender, it's understood Chelsea's interest in Ake has cooled based on information from their scouting report, according to the Evening Standard's James Olley.
Chelsea are reportedly concerned about the 24-year-old's ability to play in the heart of Frank Lampard's defense and are unsure if he can make the transition to the higher defensive line Lampard prefers to utilize.
A £40-million buy-back clause was inserted into Ake's contract when Bournemouth bought him from Chelsea for a club-record fee of £20 million. Chelsea also have first refusal on Ake.
The Blues are in the market for a defender during the winter transfer period after the Court of Arbitration for Sport reduced their FIFA-issued transfer ban. They were prohibited from signing new players last summer after world football's governing body determined the Premier League club breached rules relating to the signing of minors.
Lampard's team currently occupies the last Champions League spot in the Premier League table and has a five-point edge over fifth-place Manchester United.