At the peak of his popularity in Scotland, Paul Gascoigne decided to lampoon the rumours of his drinking and partying. As the (possibly apocryphal) story goes, at half-time during a Rangers match he made a detour on his way to the dressing-room, walked into one of the Ibrox bars in full kit and ordered a double scotch. It was Gazza’s way of having a laugh and mocking those who spoke of an imminent decline.

Ronaldinho might have wished to do the same in Glasgow two weeks ago, during Barcelona’s goalless draw with Rangers. The doom merchants looked to have the better of him. Lionel Messi, the Argentine wunderkind, had supplanted Ronaldinho as the brightest star in the Nou Camp’s firmament. Media outlets chronicled his supposed nighttime exploits, presenting him as football’s answer to Pete Doherty.

Some even coined a term, “Brazilian superstar disease”, which was allegedly afflicting Ronaldinho as well as his national teammates Adriano, of Inter Milan, who admitted to having a drink problem, and Ronaldo, whose allegedly ballooning waistline provided acres of newsprint in Madrid and Milan.

The low point came a few days before Barcelona’s trip to Ibrox, when Ronaldinho was dropped for a league match after returning late from an international qualifier in Rio de Janeiro. According to local reports he missed his flight after staying out until 11am, a feat the 27-year-old achieved by bribing nightclub staff to stay open for him and his friends.

At that point it looked as if his days at the Nou Camp were numbered. Frank Rijkaard, the Barcelona coach, had substituted him repeatedly. He had not scored for six weeks. Addressing the situation on The Times’s Game Podcast, Rijkaard said: “We are here to help, it’s our job, we do what is within our possibilities. We help as much as we can, but the main response has to come from the player – he has to be motivated and he has to know what he wants to achieve.”

For a laid-back man such as Rijkaard, it was a challenge to his biggest superstar. And on the evidence of events since that statement, Ronaldinho has risen to meet it. He scored the equaliser against Real Valladolid a week ago and followed up with a sterling performance on Sunday against Real Betis: two goals, half a dozen chances created out of nothing and a standing ovation. All of which suggests that this is not a good time for Rangers to face him.

But perhaps it was on the cards. Whatever he may have been doing off the pitch and however poor his form may have been this season, his numbers remain impressive: five goals in seven league appearances is nothing to be sniffed at. Last season, only three players scored more league goals than Ronaldinho’s 21.

Numbers, however, do not always equate to stardom, which is a far more indefinable quality. It may well be – as some conspiracy theorists suggest – that the powers that be at Barcelona have put all their eggs in Messi’s basket and that Ronaldinho, to them, is nothing more than an expensive luxury.

We will get a clearer picture when Samuel Eto’o returns from injury and Rijkaard will presumably have to decide who to leave out: the Nou Camp is simply too small for Ronaldinho, Eto’o, Messi and Thierry Henry to be on the pitch at the same time.

In the interim, Ronaldinho soldiers on. His contract expires in 2010 and, despite assurances from Joan Laporta, the club president, there have been no talks to extend it. The uncertainty remains and, if the media are to be believed, so does the hedonistic lifestyle.

Whether it is affecting him on the pitch is another matter, as Rangers could discover this evening.