Michael Probst/Associated Press
Back in the 2010 World Cup, Bayern Munich's Thomas Mueller was outstanding for Germany. After scoring five goals and contributing three assists, he picked up the Golden Boot award and was also named Best Young Player in South Africa.
Four years on and Mueller is ready to continue his status as World Cup hero for the Nationalmannschaft.
Before the 2010 World Cup, the then-20-year-old Mueller had just finished an excellent campaign in the Bundesliga, scoring 13 goals in his first full season. In a possible omen, he also scored 13 goals last season as Bayern Munich romped to their first Bundesliga title under Pep Guardiola.
With an injury ruling Marco Reus out of the tournament, Mueller becomes even more vital to the team. He is no longer an unknown quantity; he has become one of Germany's most important players.
As Kit Holden of The Daily Mail notes: "Mueller's versatility is invaluable. He is happy in any position, so long as he is attacking, and believes that 'everything depends on whether you have the right ambition for the position you are in.'"
Mueller's Germany are one of the favourites to go far this summer, and according to Brazilian legend Pele, Mueller is one of the players who strikes the most fear into the hearts of the opposition, as he told Bild (via Peter McVitie of Goal.com).
In the three warm-up games leading up to the tournament, Mueller played twice and scored once. In both games he showed his versatility. He started on the right of the attack and scored in the 2-2 draw against Cameroon. Then, in the 6-1 win over Armenia, he played the central-attacking role in Germany's 4-3-3 formation.
It is unfair to call him a centre-forward; under Joachim Loew, the German front three are very fluid in their approach. With Mueller beside Andre Schurrle and either Mesut Ozil or Lucas Podolski, all three will rotate and look for space.
This movement will be hard for the Portuguese defence to track and guard against. With Mueller on form and in the mood to emulate his performances of four years ago, Portugal will have to be wary of the 24-year-old attacker.