All the way back in 1996, Francesco Totti made a commitment. “I want to play for Roma forever, he declared. I will never move away from my city.

He was, of course, just 19-years-old at the time and like all teenagers was making all sorts of promises he couldn’t live up to (in the same interview he expressed not only his intention to marry his then girlfriend Marzia Silvestri, but the dates when he might do so. They never made it to the altar) but this was one he intended to keep. Such was his strength of feeling for Roma that Totti is said to have instructed his mother to reject an offer from Lazio back when he was just a boy playing for local side Lodigiani. Since turning pro he has turned down moves to Milan and Real Madrid, among others.

Such loyalty has served Roma well, Totti helping to bring them their third-ever Scudetto in 2001 even if they have had to settle ever since for being the bridesmaid finishing runners-up in Serie A a further five times and not the bride. Er Pupone, for his part, might have won more elsewhere but has always maintained that doing so would have meant less to him. Besides, having also won the World Cup with Italy, two Coppa Italias and the European Golden Boot his collection of silverware is still more impressive than most.

Totti’s one regret, acknowledged yesterday on the occasion of his 34th birthday, is never having tasted success in European club competition. There is time yet for him to put that right, in theory at least, and in the immediate term Roma face an important fixture tonight at home to CFR Cluj. The Romanians beat Roma at the Stadio Olimpico in their first ever Champions League group game two years ago and the Giallorossi can ill-afford a repeat. But bigger challenges loom. Perhaps none greater than the one posed by Totti himself.

I never have been, and I never will be a problem for Roma, insisted Totti yesterday but most would beg to differ. His behaviour on Saturday night, when he departed the Stadio Olimpico without even waiting to celebrate with his team-mates after being substituted during Roma’s win over Inter, was easy to downplay in the wake of a victory, but even a subsequent apology to Claudio Ranieri cannot erase the underlying issue. Previous managers can attest that Totti’s temperament has always been troublesome, but now so are his performances.

If Ranieri made any one mistake on Saturday night it was probably leaving his forward on the pitch as long as he did. Totti had seen plenty of the ball but his performance was summed up by a moment in first-half injury-time in which he miscontrolled a cross inside the area, knocking the ball out for a goal-kick. While other touches were neater his lack of energy suffocated Roma’s attempts to play on the break. An eco-friendly game, joked Sebastiano Vernazza the next day in Gazzetta dello Sport’s player ratings. Zero kilometres travelled.

The nature of Roma’s winning goal rammed home the point, Vucinic making up impressive ground as he sprinted forward to just barely get his head to the ball ahead of Lucio’s boot. Not every goal requires blistering pace, of course, but a lack of it can undermine any team. Ranieri has been chastised for returning to a 4-4-2 but it is hard to devise a tactical system in which you know one player is going to be a passenger.

It would be unfair to write Totti off as one of those just yet but at 34 he has been playing in Roma’s first team for 18 years. A persistent back problem lingers, and at different times both his right knee and left ankle have had to be reconstructed after injury. He might not have admitted it to himself just yet, but physically he is in decline. Whilst he can still have a significant role, he need not be an automatic selection for every game.

Or at least that would be the case, were Ranieri able to base his decisions purely on merit. As a Roman himself, he knows better than most that the situation is not so straightforward. For many of the club’s fans Totti is untouchable, his status summed up by the fact many in the city spent his birthday wishing each other Merry Christmas.

There were various pilgrimages held in his honour too, with a hundred or so fans walking 8.5km from Cecchignola to his birth-place in Vetulonia, while another group by the name Devotees of the Saint showed up at Totti’s house at quarter-past midnight to be the first to congratulate him. His saintly status was reaffirmed when a message arrived from the children of the Iranian woman Sakineh Mohammadi-Ashtiani, who faces being stoned for adultery and on whose behalf the striker has campaigned. We hope you live 100 years and more, read the missive.

Totti cannot go on playing for Roma quite that long but he did sign a new ten-year contract just last season that provides for him to play on until 2014, before becoming a director for the second half of its duration. Totti has said he will stop sooner if the goals dry up but one suspects it would take a drought considerably longer than the one he has been on since the penultimate game of last season.

Ranieri, in the meantime, will have a hard time working out how best to proceed. The Tinkerman’s failure to win more titles during his managerial career has led more than one pundit to question his courage but in reality he has shown often that he is unfazed by big decisions. Last season he replaced both Totti and Daniele De Rossi, Roma’s other great idol, at half-time in the derby against Lazio with his deservedly team trailing 1-0. They went on to win. Back when in charge of Fiorentina, Ranieri famously substituted the vastly popular Rui Costa 18 times in one season.

But the problem with decisions like those and the one he took on Saturday night is that you are only ever one mistake away from disaster. How, after all, would the reception in Rome have gone had Vucinic not popped up when he did? Few sided with Ranieri when, just two weeks ago, Totti criticised the manager’s decisions during the 2-0 defeat at Bayern. Sooner or later something will have to give. The evidence of the last 18 years suggests that if anyone is made to pack their bags, it won’t be Totti.

Paolo Bandini covers Italian football for guardian.co.uk and Astro SuperSport, as well as The Score. You can follow him on Twitter @Paolo_Bandini.