Pakistan opener Imamul Haq injured his left hand while batting, during the intra-squad practice match in Derby on Friday.
The left-hander was hit by a ball from pacer Naseem Shah and his injury is being assessed at the moment.
Pakistan team is currently preparing for the upcoming three-match Test series against England.
Old Trafford will host the first Test of the series starting on Wednesday August 5. The final two Tests will be played at the Rose Bowl from Thursday, August 13 and Friday, August 21.
The three T20Is will take place at Old Trafford on Friday, August 28, Sunday, August 30 and the final match of the tour on Tuesday, September 1.