Bastian Schweinsteiger's fragile left knee has been a matter of concern for weeks and the reason the Germany midfielder started the World Cup on the bench.
Now he's fit again just as the tournament gets into the decisive stage and Germany faces host Brazil in the semifinals.
Germany coach Joachim Loew considers Schweinsteiger one of his key players, the man who controls the pace of his team's game and sets quick transitions in motion once he wins the ball.
But Schweinsteiger was on the bench when the tournament started because he was not yet fully fit after a lingering knee injury that forced him to miss much of Germany's pre-World Cup training camp.
He has been in the starting line-up for the last three games, however, and said on Sunday that Loew was right to give him time to get back in shape.
"I feel very good now, I've played a lot of minutes at a high level and I can go now for more than 90 minutes, although of course I hope that it won't be necessary," Schweinsteiger said.
Loew took a gamble when he took an ailing Schweinsteiger to the 2012 European Championship. Schweinsteiger played below par and Germany lost to Italy in the semifinals. His lack of fitness was singled out as one of the reasons Germany failed to win the title.
The Germany coach had promised before the World Cup that he would take along only healthy players. But a slew of injuries to some key players, including Schweinsteiger and Sami Khedira, gave him little choice but to hope that they would recover as the tournament goes on.
"Bastian and Sami did not have their rhythm at the start. It was important for both to be fit again," assistant coach Hansi Flick said on Sunday. "We were hoping that they would get fit as the group stage progressed. We are not stubborn, we all work on a common plan and so far it has worked out sensationally."
Schweinsteiger agreed, saying he did not mind sitting on the bench despite being one of the team's leaders.
The 29-year-old midfielder has 106 caps and is one of Germany's most experienced players. Schweinsteiger believes this team is better than the one of 2010, when Germany lost in the semifinals to eventual champions Spain.
"We are more mature, we have more experience and we have a deep bench with more options," Schweinsteiger said.