Then, his career kick-started following a stunning volley that helped Uruguay tie Senegal 3-3 and almost qualify for the second round of the 2002 World Cup. After leaving the Premier League for Spain's La Liga, Forlan developed into one of Europe's most feared forwards.
Now 31 and a Europa League winner with Atletico Madrid, Forlan has the chance to shine when Uruguay returns to the biggest stage against France on Friday.
And more goals will erase any memory of the Manchester United player that once went eight months without scoring.
"I have the opportunity to play in the World Cup," Forlan said recently. "As a player, as a person and as a child, I always dreamed about it, and now I have the opportunity. So there is nothing to worry about."
He should also have no concerns about his form.
Few players have scored as consistently over the past six years as Forlan, who averaged 20 goals a season with Villareal from 2004-2007 and with Atletico since. He's twice won the Golden Boot as Europe's top scorer.
Two seasons ago, Forlan topped the Spanish league with 32 goals in 33 matches, with a highlight reel that showcased the blond-haired striker's range of talents: wicked shots from distance with his right and left foot, explosive dribbles and perfectly timed runs behind the defense.
His league total dropped to 18 in 2009-10, but he scored 10 more in other club competitions, including both goals in Atletico's 2-1 Europa Cup triumph over Fulham.
Asked if he was burnt out after a 55-match season, Forlan brushed aside the question.
"We are all in the same position," he said.
Part of the reason for Forlan's great success at Atletico has been his close partnership with Argentina playmaker Sergio Aguero. With Uruguay, he could be part of an equally dangerous tandem with Luis Suarez, who resembles Aguero with his slight stature, magnificent control and lethal finishing ability.
In qualifying for the World Cup, Forlan led Uruguay with seven goals. Suarez, the 23-year-old Ajax player, led the team with five assists.
"The team has improved," said Forlan, who scored in Uruguay's 3-1 friendly win over Switzerland in March and a 4-1 triumph over Israel last month.
Uruguay, a two-time world champion (1930 and 1950), hasn't advanced past the round of 16 at the World Cup since reaching the semifinals in 1970. It squares off Friday night in Cape Town against France, the runner-up in 2006, but a team that has struggled recently.
Mexico and host South Africa are also in Group A.
Forlan played down France's poor form, which included a stunning 1-0 loss to China.
"I look at the friendly games just to analyze how they were playing," he said. "I do not keep in mind the results. It was a friendly match and the result doesn't count. The World Cup is another competition and they will not play the same."
Associated Press writer Marianela Jimenez contributed to this report.