He was once held up as a symbol of Pakistan's unexpectedly inclusive society - a humble Christian footsoldier and son of a railway platform sweeper, who had overcome his inauspicious origins to cement a berth in his national team's middle order.
Now, however, he sports a beard that rivals Saeed Anwar's as the most fulsome in the game, punctuates his sentences with "Bismillah" and "Insh'allah", and performs the sadja instead of the sign of the cross whenever he reaches a significant landmark. Oh, and he's become quite some batsman as well.
Last year, Yousuf Youhana - the sumptuous, flashy, dreamy veteran of 59 Tests and 202 one-day internationals - hung up his batting gloves for good. Instead, out of the pavilion emerged Mohammad Yousuf. It was suggested in some quarters that he had renounced his Christianity some three years earlier, but from the moment his decision was made public, his career really took off.
Before his conversion, Yousuf had been averaging 47.46 - excellent stats on the surface, though there had been few memorable moments and several where it appeared he had cashed in while the going was good. Only one century out of 13 had been made in the second innings, for instance, and the four that had contributed to victory came against Bangladesh, Zimbabwe and West Indies - hardly the strongest attacks in the game.
In his eight matches since his conversion, however, Yousuf's average has leapt up to 83.38, and England's bowlers especially have borne the brunt of his onslaughts. The style still remains but it is the substance that is so different. No longer does Yousuf flirt at everything pitched up for his cover-drive - he is more judicious in his defence and more aware of his responsibilities as one of the rocks of Pakistan's middle order.
Consecutive double-hundreds against England have confirmed his appetite for the long haul. His 223 at Lahore in December was the insatiable march of a man who had dawdled for long enough, as he ground a demoralized opposition into the Punjab dust. At Lord's this week, however, he produced something else entirely - from the depths of 68 for 4, he found the mental strength to push on and on and on, finally falling for 202 out of a total of 445.
It was not the most spiteful pitch that Yousuf will ever encounter, that's for sure, and so he may not yet have entirely dispelled the notion that he cashes in when the going is at its best. But the pressure of the occasion could hardly have been more intense, as Yousuf joined Mohsin Khan on the Lord's honours boards as only the second Pakistani to record a double-century at the home of cricket. He's a man at the top of his game, and England fear his arrival at the crease every bit as much as they rejoice in the rare occasions they actually see the back of him.
What he says
"Everything is because of Allah, we can't do without him. I converted and after that my performances have improved because of the discipline. I pray five times a day. When you are praying you are very disciplined. The first prayer in the morning is at 4.30am, the second at teatime, the third after the game and the next two are at 9.30pm and 10.45pm. I haven't changed my way of playing, or the way of my game, just the way of my life."
What they say
"I'm ashamed to give him my name after what he has done." Of all the critics of his decision to convert, it was Yousuf's mother who was the most outspoken. The pair are reported to have since patched up their differences.
What you may not know
If you're an Englishman, the biggest mystery is where to bowl to him. Nine matches have realised 1019 runs, including four centuries in 15 innings at the impressive average of 67.93.
What the future holds
He's up to No. 5 in the world rankings - his best-ever position and his highest tally of points as well - and at the age of 31 he is very much in his prime. Inzamam-ul-Haq is unlikely to play on much beyond the next World Cup, which means that there could be a captaincy vacancy in the not-so-distant future. Cynics have suggested that may have his main motivation for conversion, while critics would tell you he's not the sharpest tool in the box at any rate. But if Pakistan are in need of a man who'll lead by example then, on current form, they need not look any further.
Andrew Miller is UK editor of Cricinfo