Vaughan, the England captain, has been steadily increasing his training after injuring his knee a week ago, and he now appears to be on the brink of making a remarkable recovery.
When Vaughan collapsed in a heap at the Bagh-i-Jinnah ground in Lahore five days before the first Test many felt that his tour of Pakistan was over.
Yet the sight yesterday of the England captain jogging lightly round the Multan Stadium before the start of play, and batting in nets adjacent to the pitch during the lunch break, was enough to put a smile on the face of any watching England fan.
Vaughan began testing the knee on the first day of the Test and yesterday he batted twice at the ground before spending 30 minutes on a bicycle and stepping machine at the hotel gymnasium.
Coming through sessions like these, when conditions are relatively controlled, is one thing but the real test will come when Vaughan has to imitate the movements he will make in a match.
Stopping, starting and twisting suddenly are the actions that aggravate a knee joint, and Vaughan will be expected to do all of these when he is running between the wickets or standing in the field.
At some stage during the next five days Vaughan needs to bat for an hour or two and vigorously test the joint. Only when he has come through this will he feel confident enough to declare himself fit.
"Michael had a few throw-downs in the nets and did a light run. But it is too early to say whether he will be fit for the second Test," the England team's spokesman, Andrew Walpole, said.
The were more anxious looks among the England medical staff yesterday as Kevin Pietersen gave the team a fright when he hurt his arm, and Pakistan were also given cause for concern when Mohammad Yousuf injured his left shoulder while fielding. He later went to hospital for a scan.
If Vaughan proves his fitness it will place England's selectors in a difficult position. Vaughan would obviously come straight back into the side. But at whose expense? Paul Collingwood would have been selected ahead of Ian Bell had Vaughan not withdrawn from the team, but the Durham all-rounder has had a quiet match to date. Bell, meanwhile, scored an attractive 71 in England's first innings.
It would be tough on Collingwood to leave him out after one match, but Bell could make it even harder for the selectors if he were to guide England to victory with another good score.
* The Royal Mint has produced the official Ashes Winners' Medal to celebrate England's victory over Australia this summer. One side features the Ashes urn surrounded by the words "England 2005 Ashes Test Winners," while the reverse depicts the exact moment a ball hits the stumps.Reuse content