President Uhuru Kenyatta had earlier said that if any of his ministers are mentioned in corruption they will have to step down.
Following serious accusations of corruption against Henry Rotich, here are some of the people likely to succeed him.
Transport PS Esther Koimett and her boss James Macharia are among the potential appointees for the job. However, due to the power-sharing deal between Ruto and Uhuru, Koimett may be an easy pick.
Esther Koimett is a career investment banker, she has had a 25-year-old career in government. She has previously served as the permanent secretary in the Ministry of Tourism and as the managing director of Kenya Post office bank.
She holds a BComm degree from the University of Nairobi and an MBA from the same institution. She also hails from Keiyo, similar to Mr Rotich.
She has previously worked as an investment secretary at the Treasury and on the privatisation commission.
Other potential individuals being considered Mr Adan Mohammed CS of industrialization and former Barclays CEO, Mr Nelson Gaichuhie CAS National Treasury and former Subukia MP, Dr Geoffrey Mwau senior adviser to the CS Treasury and current Head of public service Joseph Kinyua.