Uruguay surprised the world with a run to the semi-finals of the last World Cup, but will need to be at its best to even make it to the knockout stages four years on.
The South Americans have twice won the biggest prize in football, but an entertaining run to the semis in South Africa was their best World Cup showing since lifting the trophy in 1950 - ending a spell over half a century in the international football wilderness.
The fourth-place finish in 2010 was followed up by a 2011 Confederations Cup title, but Oscar Tabarez's side limped through qualification for the 2014 showpiece, dropping out of the top-four qualification places thanks to just seven wins in 16 qualifying games. A 5-0 win over Jordan helped Uruguay to Brazil via the play-offs, but its fortunes didn't improve at the draw, with Italy, England and Saturday's opponents Costa Rica joining La Celeste in arguably the toughest of all of the groups.
The key to Uruguay's chances will hinge on its big-name attacking triumvirate. Edinson Cavani became the sixth most expensive footballer in history when he moved from Napoli to Paris Saint-Germain last summer, and he didn't disappoint in a debut season that saw him net 25 goals in all competitions despite sitting out over a month of the season with a thigh injury. Cavani will be partnered in attack by the English Premier League's Player of the Year. Luis Suarez was one of the faces of the 2010 World Cup - not all for good reasons - and the Liverpool striker has barely left the headlines since then, with a string of controversial incidents running alongside his development into one of the world's standout attacking players. The 35-year-old Diego Forlan may not be the player he once was, but the former Manchester United, Villarreal and Atletico Madrid forward has the vision and passing range to play a huge role in Uruguay's counter-attacking game throughout the tournament.
Uruguay's forwards will need to hit the ground running given the crucial nature of Saturday's opener in Fortaleza, but fitness concerns mean that Suarez's participation in the first group game remains in doubt.
"We have no set deadlines," revealed Tabarez. "I don't know if we'll have him for the first match, for the second, for the third. If it were up to me, Suarez would play tomorrow."
Whether Suarez plays or not, a win over Costa Rica would hugely boost Uruguay's chances of making it out of the group, as three points would give Tabarez the chance to set his team up to play on the counter-attack against the two defensively vulnerable European sides in the remaining two group games.
"The first game is vital," said Uruguay goalkeeper Fernando Muslera. "Costa Rica are not the underdogs in the group. They've got players in Europe, they've really come on, and they've been a tough nut for us to crack in the last few years."
Most pundits have tipped Costa Rica to leave Brazil with nothing from three Group D matches, but its opponents would do well not to underestimate a side that is defensively well-organised and capable on the counter-attack. A broken leg ruled out arguably Costa Rica's best player, full-back Bryan Oviedo, but striker Joel Campbell will provide a direct goal-threat and Fulham fans will be surprised to hear that playmaker Bryan Ruiz has looked a top-class creative option when playing for his country.
Any points from the opening game against Uruguay would leave Costa Rica in a fantastic position to shock Italy and England in its remaining group games, and manager Jorge Luis Pinto has promised that his players will leave Brazil with no regrets.
"We will play without fear," said Pinto. "We face three world champions and we can take them all on. What we feel is joy and motivation.
"We respect England, Italy and Uruguay. But they should know that we can play football too."
Brazil 2014 will be Costa Rica's fourth World Cup out of the last five, but it hasn't made it to the knockout stages since 1990.
Saturday's game in Fortaleza will be the opening match of Group D, three hours before Italy and England face off in Manaus.