The replacement for England's Bell will be decided later, Khan added.
While Islamabad United lost Bell, Lahore Qalandars on Sunday confirmed that AB De Villiers is "perfectly all right" to play.
They said that while there was minor stiffness in his back and he was rested in the second innings of Lahore's match against Quetta, he will return during the team's next match.
However, the Qalandars' management also announced that Brendan Taylor has been ruled out following an injury on his calf muscle and will not play the remaining PSL4 matches.
They noted that as they already have six foreign players in the current roster, therefore, at the moment, a replacement for Taylor isn't required.
Lahore's management added that Shaheen Shah Afridi, who was also rested against the Gladiators, will be available for the next match.
Qalandars captain Hafeez has already been ruled out of the tournament after he fractured his thumb during the match against Karachi Kings on February 16.
Veteran batsman Salman Butt replaced Hafeez.