England captain Michael Vaughan may miss the first Test against Pakistan unless a knee injury which he suffered on Monday responds to treatment, the team doctor said.
Vaughan twisted his right knee on the second morning of the three-day tour match against a Pakistan A team. The first Test starts in Multan on Saturday.
Vaughan twisted the same knee in an accident in the nets before the series against New Zealand, when he missed the first Test last year.
England's doctor Peter Gregory feared the injury may rule Vaughan out of the three-Test series.
"The last time he didn't tear the cartilage but if there is a tear then he would be doubtful for the whole series," he said. Gregory said the knee was still very sore "and it's going to be complicated because he hurt the knee before. It's very difficult to say but we need 24-48 hours to see how he responds to treatment."
Vaughan, who had yet to score, was injured while going for a run and fell to the ground in pain. He walked off the ground to get treatment. The England captain had an operation on the same knee in Australia two years ago.
Vaughan came into the second tour match needing some batting practice. He managed just nine and nought in the first game at Rawalpindi last week and 17 in the first innings of the current match.