We know about the stars who need to produce for their teams to advance in the World Cup. But don't overlook these unsung and underrated players who will play vital roles in South Africa.

Jonas Gutierrez, Argentina

At first glance, Jonas Gutierrez's inclusion in the Argentine starting lineup looks like one of Diego Maradona's crazier decisions, which is saying something given that Martin Palermo is on the roster. But closer inspection reveals that in this instance, there is a method to the madness.

At present, it looks as though Maradona will place immense responsibility on Juan Sebastian Veron to orchestrate the Albiceleste's attack, and there is concern that the 35-year-old might not have the range or stamina to effectively attend to his defensive duties in the center of midfield.

This is where Gutierrez factors into the equation. The Newcastle United midfielder is supremely athletic and is expected to provide some defensive help to Veron and Javier Mascherano by sliding in centrally from his spot on the right side of midfield, especially when Angel Di Maria bombs forward on the opposite wing. The hope is that this will save Veron from having to expel too much energy and allow him to concentrate on setting the table for the likes of Di Maria, Gonzalo Higuain and Lionel Messi.

If Argentina goes far, expect the usual suspects to get the accolades, but Gutierrez's contribution will be critical as well.

-- Jeff Carlisle

Nigel de Jong, Netherlands

For all their attacking firepower, the Dutch will rely heavily on someone playing behind all the men first in line for glory: Nigel de Jong. De Jong, a holding midfielder, perhaps best known for injuring American winger Stuart Holden when the Netherlands played the U.S. on March 3 in Amsterdam, will play a crucial role. The Dutch will have three all-out attackers, and a playmaker in Wesley Sneijder who concerns himself primarily with getting forward. The only other midfielder left aside from de Jong is Mark van Bommel who, while uncompromising, has a preternatural talent for losing his man when he should most stick with him. Playing in front of a back line that is suspect at best and unworthy of a World Cup team with serious aspirations at worst, de Jong will be counted on to hold things together defensively. That means covering for van Bommel, covering for the others flitting off to shoot at the other goal, plugging holes, nipping counterattacks in the bud, doing the dirty work in midfield and helping out on defense.

That is to say, without a consistently sterling performance from de Jong, the Dutch, picked by many to advance far, are in dire straits.

-- Leander Schaerlaeckens

Peter Crouch, England

Wayne Rooney justifiably grabs most of the attention when discussing England's squad, and right behind him lie Frank Lampard, Steven Gerrard and Rio Ferdinand (right or wrong). Theo Walcott, when he's on his game, is highlight-reel material.

But Peter Crouch doesn't get the credit he deserves. Sadly, most still think of Crouch as a beanpole striker who's only good at holding up the ball and winning headers. Yes, he can do that, but Crouch is technically very adept and, since becoming a regular at club level, has scored his fair share of goals everywhere he's played. That includes England -- Crouch has netted 20 goals in 37 appearances. If Rooney isn't completely fit, then we could see Crouch and club teammate Jermain Defoe up front at some point. He won't disappoint.

Bring back "the robot."

--Ravi Ubha

Andres Guardado, Mexico

Most of the publicity surrounding this promising generation of young Mexican players has centered on Giovani Dos Santos and Carlos Vela, and more recently Javier Hernandez. It's easy to understand why, considering the clubs those players have been affiliated with: Barcelona, Arsenal and Manchester United.

But the Mexican who has accomplished most in European soccer over the past few years, with the exception of Rafael Marquez, is probably Andres Guardado. Only 23, the midfielder has been a fixture for Deportivo La Coruna since a transfer in the summer of 2007, and now looks ready to take on a bigger role than ever with El Tri in South Africa.

A minor injury that cost Guardado the last few weeks of the Spanish season may have been a blessing in disguise, as the winger has shown up in Mexican camp with energy and enthusiasm, ready to play a major part in Javier Aguirre's attack. El Tri is set to focus on wing play, and Guardado will be a huge asset on the left, but he also looks capable of taking on more responsibility in filling the up-for-grabs central role in attacking midfield, where he would essentially run the offensive show for El Tri. Look for Guardado to have a monster game against South Africa in the opener, and help guide Mexico's attack throughout the tournament.

--Brent Latham

Branislav Ivanovic, Serbia

Chelsea is a team of superstars, as we were recently reminded (unpleasantly for some) when it won the Premier League and FA Cup. John Terry, Ashley Cole, Frank Lampard, Didier Drogba -- they're some of the biggest names in the game. Not included on that list is Branislav Ivanovic, a Serbian defender who started the 2009-10 season for Chelsea as a backup to Jose Bosingwa. But as the months wore on and injuries piled up, Ivanovic worked his way on the team and became a critical part of the Blue's defense at right back, but also showed the versatility to play center back. Ivanovic isn't a sexy player who draws attention to himself, but on the Serbian national team alongside Nemanja Vidic, another superb defender, he should play a key role in helping his country keep many clean sheets.

--James Martin

Gilberto Silva, Brazil

The choice of a World Cup winner, who also happened to be ever-present in Brazil's Confederations Cup-winning side just a year ago, may raise an eyebrow or two, but in spite of his impeccable résumé, that the 33-year-old midfielder continues to represent his country is a tribute to Silva's defiance of the odds.

Following a disappointing campaign in Germany four years ago, there were calls for Gilberto to end his Brazil career. However, new coach, Dunga, himself a workmanlike midfielder during his playing days, kept faith with the veteran, even after he fell out of favor at Arsenal and was sold to Panathinaikos in 2008.

In 44 competitive games with Gilberto in its side, including 16 qualifiers on the road to South Africa, Brazil has lost just three times. He may be underrated or, indeed, unrated by some fans and pundits, but his national team coach remains a fan, meaning Gilberto is as important now as he has ever been.

--Andrew Hush