The Premier League transfer window may have shut but they can still sell players to European teams and Monaco have until September 2 to get a deal done to bring the midfielder back to the Stade Louis II.
Monaco are in desperate need of reinforcements after a poor start to the season as they have just one point from three games so far, and face a tough trip to Strasbourg on Sunday.
The holding midfielder joined Chelsea in a £40million switch from Monaco in 2017 after helping them claim the Ligue 1 title.
Bakayoko was a key member of that Monaco side, but while former team-mates Kylian Mbappe, Bernardo Silva, Fabinho and Benjamin Mendy have gone on to star for their new clubs, the 25-year-old has fallen completely off the radar at Chelsea.
The one-cap France international has managed just 29 Premier League appearances during his time with the Blues and spent last season on loan at AC Milan.
The Rossoneri did have the option to land Bakayoko outright for €35m this summer but decided against pursuing a permanent transfer as the midfield enforcer struggled for consistency last term.
Bakayoko hasn't made an appearance for Chelsea this season under Frank Lampard and hasn't even been included on the bench in any of their four games so far.
French publication RMC have now reported the midfielder has agreed terms with Monaco and a transfer is expected to be concluded in the coming days, although Chelsea are still weighing up the offer.
Monaco hope to take Bakayoko on loan with the option of a permanent €35m deal next summer and that could be the issue holding the deal back.
As Monaco would have an option, rather than an obligation, to buy the player outright next summer Chelsea could be left in the same situation at the end of the season - with Bakayoko back with the squad for pre-season and again searching for a new home.
The former Rennes man is under contract with Chelsea until 2022 and the Premier League club may want assurances that a permanent move to Monaco will be completed next summer before they sanction a deal, although with no further interest in Bakayoko and time running out, the Stamford Bridge club may have to accept the current offer if he is to depart this summer.