The canny leg-spinner is apparently recovering well according to the PCB but he has been asked by the medical team to rest until he reaches full fitness.
Shadab's injury occurred in the first intra-squad warm-up game in Lahore on October 23, a week prior to the start of the ODI series.
While Pakistan prevailed in the ODI contests by a slim margin of 2-1, Shadab's absence was particularly felt during the final 50-over match in Rawalpindi.
Pakistan went into the game with Iftikhar Ahmed as the frontline spin bowling option and eventually faced defeat in a thrilling Super Over finish.
Pakistan captain Babar Azam later lamented the agonising loss and expressed disappointment at botching the opportunity to gain an additional 10 points in the ICC World Cup Super League.
Pakistan have the option of handing Usman Qadir his maiden international cap or inducting Zafar Gohar into the playing XI for the opening T20I as the second spinner.
The three-match T20I series will conclude on November 10, following which the fifth edition of Pakistan Super League (PSL) will resume on November 14 in Karachi.