Paolo Guerrero is fit to start Peru's World Cup opener against Denmark on Saturday (kick-off 5pm BST) after being reprieved from a doping ban in time for the tournament.
Peru's all-time top-scorer missed the play-offs against New Zealand after he tested positive for a cocaine byproduct contained in a tea.
Guerrero said he ingested the drug unknowingly when he thought he had been given herbal tea for a flu, and his ban has been temporarily lifted pending an appeal, meaning he can feature at the World Cup.
There have been questions about whether the 34-year-old would be fit enough to play a key role, but head coach Ricardo Gareca said: "Whatever happened in the past, Paolo is very, very fit, he is training at a very high level and he really is ready to play.
Guerrero scored twice on his return in a 3-0 win over Saudi Arabia in a friendly on June 3.
"Paolo is playing very well and he is very, very happy, preparing, and in a very good situation," Gareca added, without disclosing if he would be in the starting line-up.
Peru are making their first appearance in the finals since 1982 while Denmark are returning to the tournament after missing out in 2014.
Tottenham's Christian Eriksen will be a key player for the Danes after topping the scoring charts in qualifying with 11 goals, and manager Age Hareide wants the same attacking prowess against the Peruvians.
"Peru and Denmark is an all important match. France is certainly the favourite," Hareide told reporters.
"If we want to occupy the second place then points tomorrow is very important. We are going to have to go all out tomorrow to see if we can win the match."
France and Australia meet in the other Group C clash earlier in the day.
With Guerrero available to start, Peru have no injury concerns.
There will be a few recognisable Premier League faces in the Danish team, with Leicester goalkeeper Kasper Schmeichel and Chelsea defender Andres Christensen both expected to start alongside Eriksen.
This will be the first ever encounter between Peru and Denmark.
One of the original participants in 1930, Peru qualified for their fifth World Cup after beating New Zealand in the play-offs. It's their first appearance since 1982, which is the biggest gap of years (36) between participations at the World Cup for any of the 32 teams qualified for the 2018 tournament.
Peru have faced the eventual World Cup winner in each of their four previous World Cup appearances (Uruguay in 1930, Brazil in 1970, Argentina in 1978, Italy in 1982).
Denmark have reached the knockout stages in three of their four previous World Cup appearances but never progressed past the quarter-finals (1998).
Only two of Denmark's 16 games at the World Cup have ended in draws (W8 L6). Meanwhile, they have kept only one clean sheet in their last 11 World Cup games, against France in 2002 (2-0).
Top scorer (11) and assist provider (3) for Denmark during the 2018 World Cup qualifiers, Christian Eriksen was directly involved in 56% of his team's goals. Six of his 11 goals came from outside the box.
This will be a hard game for Denmark as Peru are a good team - they play some decent football and should not be underestimated. They have no massive stars in their team, but they get the ball down, pass and move, so I think this will be a good game and I am going for a 1-1 draw. Denmark have done well, but Peru could be the dark horses to come out of what is a hard group.
PAUL PREDICTS: 1-1 (5/1 with Sky Bet)
Joint favourites to open the goal scoring are Denmark's Nicolai Jorgensen and Peru's Paolo Guerrero who both sit at 9/2, while Christian Eriksen is 6/1 to break the deadlock. Denmark are 100/1 to win the World Cup whereas Peru is 150/1 to lift the trophy.