The 21-year-old Ghanaian left-back has been linked with the Blues for much of the summer and it appeared that perhaps a deal was set to fall by the wayside prior to the new English season kicking off.
However, Rahman's agent has revealed that personal terms have been agreed and all that is left is the fee.
"It is only the clubs that have to find an agreement. We on our side are agreed," Sascha Empacher told BILD.
Chelsea have previously been linked with a £17.5million move for Rahman but it remain to be seen what they will pay for the promising defender.