ONE swallow does not make a summer, but it can be a pointer towards better times ahead. So while it would be wrong to get too carried away with Ricky Alvarez’s performance against Championship opposition on Tuesday night, at least the Sunderland winger has shown he has not completely lost the abilities that once made him one of the most sought-after players in South America.

In his previous six months as a Sunderland player, which admittedly were pockmarked with a succession of frustrating injuries, it had been hard to see what anyone saw in him, let alone deduce what convinced Gus Poyet and Lee Congerton to agree to a loan deal that includes a clause for a permanent switch from Inter Milan this summer.

Clearly, Alvarez will have to showcase his skills against better sides than Fulham before he can be regarded as an integral part of a Sunderland side that is finally showing signs of improvement, but with his blistering pace, inventive trickery and willingness to run at an opposition defence, the 26-year-old has at least displayed a skill-set that makes him something of a one-off in the Black Cats squad.

It is hard to imagine any of his team-mates - and former England international Adam Johnson can be included in that – scoring the goal that did so much to book Sunderland’s place in the FA Cup fifth round, and having been understandably reluctant to put too much stock in Alvarez’s talents so far, Poyet will surely have to throw caution to the wind when it comes to his treatment of the Argentinian in the next few months.

If they are going to invest £7.5m in the winger in the close season, the Sunderland hierarchy need to be convinced that Alvarez can prove similarly effective against top-flight opposition. His previous record suggests that he can, although achieving a consistency of performance has sometimes proved elusive.

As part of a Velez Sarsfield team that reached the semi-finals of the Copa Libertadores – South America’s equivalent of the Champions League – Alvarez was close to joining Arsenal before eventually completing a €12.8m move to Inter Milan.

Praised for the individual flashes of brilliance that illuminated a Velez side with a strong work ethic, Alvarez was being touted as South America’s next superstar when he moved to Milan. His time in Italy did not work out as planned, partly because he was often asked to play in a trequartista role that did not really suit him and partly because a serious knee injury sidelined him for more than six months at an early stage of his stay.

Poyet remembered his talents though, and while he was quick to stress that Alvarez was not signed as a direct replacement for Fabio Borini, he clearly had higher hopes for his fellow South American than have been realised so far.

Tuesday’s performance was the first indication that that could change. Alvarez now has three-and-a-half months in which to convince Poyet and Congerton that he can provide a long-time answer to Sunderland’s creative problems. If he can do that, his summer price tag should not be an issue.