The 28-year-old Kean hails from Maharashtra's Thane region and has also played in the cash-rich Indian Super League.
According to a statement issued on Friday, the left-half has been handed a one-year contract by the Delhi-based outfit.
Ken made his professional debut with Mohun Bagan in a 3-1 win over Aizawl FC in the 2015-16 I-League season. He also represented the Kolkata giants in the I-League in 2016-17 edition.
Lewis later played for now-defunct Delhi Dynamos and Pune City in the ISL.