Khan, 28, missed the drawn first Test at Lord's last week but was back on the field for his country's four-day match against Northamptonshire, which began on Thursday.
If he comes through the game unscathed, Khan is certain to return to the Pakistan Test team at Old Trafford, Manchester on July 27.
Khan, who has scored five hundreds in his last 11 Tests, is captaining Pakistan at Northampton as coach Bob Woolmer rests several first-choice players including regular skipper Inzamam-ul-Haq.
Woolmer said: "He is 100 percent fit and will be back and firing, which is very good news for us."
Pakistan all-rounder Abdul Razzaq, leg-spinner Danish Kaneria and Lord's double-centurion Mohammad Yousuf all sit out the Northamptonshire warm-up.
Team manager Zaheer Abbas hinted leg-spinner Mushtaq Ahmed, currently playing county cricket in England with Sussex, could be called into the side at Old Trafford if the pitch looks like it will take spin.
The Pakistan Cricket Board have sanctioned his inclusion as an additional member of the touring party and Abbas said: "If we are going to call him for Old Trafford we have to play him.
"He has been playing here and has done very well so there is no need for him to get a game beforehand."