It will be Mujeeb's second stint with the franchise after he got 12 wickets last season.
BBL is set to get underway on December 17.
Melbourne Renegades released him after an underwhelming season in the previous edition.
Russell single-handedly won KKR many matches this season and has been the MVP of the season.
It was earlier reported that De Villiers was close to inking a record deal with one of the teams.
He was recently blessed with a baby and is currently playing in the IPL.
"It was a very successful period for the club"- Marsh.