Manuel Queimadelos Alonso/Getty Images Barcelona has a problem. Not the kind most clubs deal with, but one no less vexing -- how do you improve on that which is already perfect? Barcelona has a problem. Not the kind most clubs deal with, but one no less vexing -- how do you improve on that which is already perfect?

How do you improve on the already perfect?

It's a question that has troubled Barcelona coach Pep Guardiola more than most. With his side widely assumed to have attained some sort of soccer nirvana, the prospect of building on its current success is a uniquely challenging one, not to mention eye-wateringly expensive for a club whose president, Sandro Rosell, has been forced into embarrassing admissions of the club's financial difficulties since taking the job last summer.

Nevertheless, for the second time in the space of three seasons, Guardiola is calling on outside help to take his lauded side a level further, with Udinese's star man, Alexis Sanchez, his preferred choice.

That Barcelona is looking to augment a squad that appears a tad thin compared with that of Real Madrid is no surprise -- the second Champions League final win in three years was once again achieved with a specialist midfielder playing in central defense. But the recruitment of a further attacker to supplement a team that hit 137 goals in all competitions last season perhaps is.

The decision seems even more curious when one considers all three of Barca's current attacking trio -- Pedro, David Villa and Lionel Messi -- were goal scorers in the Champions League final win over Manchester United at Wembley in May. Yet Guardiola's astonishing coaching record at the club has been based on restlessness, a fear of inertia and a desire to constantly strive for more.

Hence only a select few in the side (perhaps Messi, Xavi and Andres Iniesta) can feel their places guaranteed. Pedro is likely to be the most under pressure from Sanchez's proposed arrival, but recent speculation has suggested that the Catalans might consider a lucrative English Premier League bid for Villa.

What is sure is that the potential arrival of either Sanchez or the suggested alternative, Villarreal's New Jersey-born Italy international Giuseppe Rossi, would be to facilitate an adjustment in Barcelona's forward style. The biggest leap arguably would be the introduction of Sanchez. A jet-heeled winger blessed with extraordinary close control, his incorporation into the front three would provide more width to the attack.

Perhaps what sealed Guardiola's conviction that Sanchez is the one was the transition of his role at Udinese last term. Coach Francesco Guidolin's decision to allow the Chilean license to roam infield -- coupled with the confidence gleaned from a positive 2010 World Cup performance -- paid dividends. Sanchez had a best-ever goal-scoring season, notching 12 in 27 starts, dwarfing a previous best of five in a Serie A season. As well as giving reason to believe that the 22-year-old can weigh in with his share of goals in La Liga, the numbers are added proof that his star is inexorably on the rise.

Rossi's agent, Federico Pastorello, said last week that any deal to take his charge north to the Catalan capital was "dead," but the feeling prevails that Rossi was only a backup if a deal for Sanchez fell through, a harsh classification for such an accomplished forward. At 24, Rossi is Sanchez's senior by just more than 18 months but has the advantage of significant experience of the Spanish domestic game. He has just completed his fourth season at Villarreal and has never failed to hit double figures in a campaign. His healthy 2010-11 return of 18 in 35 matches was his best yet.

[+] Enlarge Claudio Villa/Getty Images Would Alexis Sanchez help Barcelona hone its fluid attacking game?

Rossi's style shows more of an all-rounder than Pedro -- a fine goal scorer, but Rossi also can drop deeper into a "false nine" position to create and link play. His versatility and his personal growth in an environment of highly attractive football at Villarreal make him a great fit for the amorphous attacking style that Barcelona has made its own. With his ability to drop off and his fluent left-footed gait, he could even partially cover the blow of the unthinkable -- an injury to Messi.

Nevertheless, the substantial outlay required for either player is a risk for the club, with Udinese demanding anything up to 50 million euros for Sanchez (the sticking point of the deal with the winger thought to have already agreed terms with Barca) and Rossi's buyout clause set at 40 million euros.

The last alteration to Barca's attack was the addition of Villa, one of the more low-risk 40 million euro signings you'll ever see. Spain's record goal scorer, Villa already had seven seasons of top-flight prolificacy behind him when he arrived in Catalonia. His 23 goals in 50 matches last season included the beautiful dipping shot that sealed the Wembley final.

The specter of the failure of the Zlatan Ibrahimovic signing looms large over any prospective Sanchez/Rossi deal. His arrival in summer 2009 was a bold move, designed to add finesse, adaptability and a Plan B to Barca's attacking options, while sacrificing the visceral power of Samuel Eto'o. In the process of attempting to evolve, the Champions League was lost and Ibrahimovic was jettisoned, at no little expense. The Swede's acquisition had cost an estimated 70 million euros, and 12 months later he was loaned to Milan, with the Italians given an option to buy for a knockdown 24 million euros -- a loss Barca could ill afford.

The terms of Ibrahimovic's failure are highly subjective. In fact, the difference between his and Villa's stats for their respective debut seasons at Camp Nou are fairly similar. Ibrahimovic scored 21 in 41 games, hitting 16 in 29 league matches, while Villa scored 18 in 34 La Liga appearances. Quite apart from the former's perceived arrogance, the suspicion lingers that Villa was indulged through his own dry spells (he scored just once in the league after February's 3-0 win at Mallorca) as he was more compatible with Barca's established style, as a mobile, more team-oriented player, and thus easier for the team to carry when not playing well.

So perhaps the assimilation of Sanchez -- or even Rossi -- into the Barcelona system is only half of the battle. This time, maybe Guardiola will have to be prepared to stick to his decision to evolve the squad and find a way to make it work if the going is rough, instead of offloading the player and asking the Barcelona board to pick up the check.

Andy Brassell is a freelance soccer writer for ESPN.com.