The Blues have moved to address their need for a left back by snapping up the 21-year-old Ghana international.
Chelsea has completed the signing of Augsburg defender Baba Rahman for an undisclosed fee.
The Premier League champion had been looking for a new left back following Felipe Luis' return to Atletico Madrid earlier this summer but initially struggled to agree a deal with the German outfit for their 21-year-old Ghana international.
Augsburg chairman Jonas Hoffman stated that the club had no need to sell, claiming that they would not even entertain any bid under £14 million ($22 million).