Singh, who would be 16 on May 17, thus become the youngest player picked for the Mumbai senior side after retired great Sachin Tendulkar in the 1980s.
Varanasi-born Singh took seven wickets for the Mumbai under 16 side against Punjab in the drawn four-day Cooch Behar Trophy final at Mohali, including a five-for in the first innings, in a Punjab total of 462 that fell short of the visitors' 466.
Also in the squad are Suryakumar Yadav and Sarfaraz Khan who were issued show cause notices for their unacceptable behaviour by the MCA to which they had replied with an apology for their conduct.
The Mumbai selection panel is headed by Sandeep Patil and the others in the committee are Milind Rege, Nishit Shetty and Sanjay Patil.
Mumbai will play against Baroda on the opening day of the four-day tournament to decide the two qualifiers from the zone for the inter-zonals for the Syed Mushtaq Ali trophy tournament which follows.