Uruguay must recover from the shock of losing star player Luis Suarez, who was kicked out of the World Cup for biting an opponent, if they are to stop high-scoring Colombia in an all-South American, second-round clash on Saturday.
Uruguay have long relied heavily on Suarez in attack and the controversial striker scored half of their four goals so far in the competition in Brazil.
He was thrown out of the World Cup on Thursday for biting Italian defender Giorgio Chiellini in a group match, dealing a huge setback to Uruguay, who battled their way to the semifinals of the 2010 tournament in South Africa.
Colombia head to the Maracana stadium in Rio de Janeiro in more buoyant mood, having won all three of their group games and racked up nine goals in the process, a tally surpassed so far only by the rampant Netherlands.
There had been fears that the loss of striker Radamel Falcao to injury before the tournament would be a big blow for Colombia, appearing at their first World Cup in 16 years.
But Falcao’s understudy Jackson Martinez has been one of the tournament's revelations so far, helped in large part by playmaker James Rodriguez.
With those two in fine form, Colombia, under Argentine coach Jose Pekerman have wowed crowds in Brazil with the kind of fast, flowing play that the locals demand of their own team.
They have also entertained fans with their salsa-inspired goal celebrations.
A place in the quarterfinals against either Brazil or Chile is at stake on Saturday and Uruguay will be seeking to channel the spirit of 1950 -- when they shocked Brazil by beating them to win the World Cup in Rio.
It will probably fall to veteran striker Diego Forlan to take the place of Suarez in the starting 11 in the Maracana as he did in their shock opening loss to Costa Rica in Group D while Suarez was still completing his recovery from injury.
Uruguay played poorly in that match which they lost 3-1 but looked better in their next, a 2-1 win over England when Suarez scored both their goals.
After overcoming Italy 1-0 in the now infamous game in which Suarez lost his self-control, they must now cope without him again. Captain Diego Lugano vowed the team would not be distracted by his loss.
“Nothing will hold us back,” Lugano wrote on his Facebook page. “We will press on with humility, unity, determination, aware of the mistakes that have been made and with our heads always held high.”
With both teams likely to bring huge numbers of fans to the Rio on Saturday, security at the Maracana will be tight.
Around 200 Chilean fans stormed in for their team's first-round match against Spain. A few days earlier, a handful of Argentine fans climbed over the Maracana's perimeter fence.