United States captain Carlos Bocanegra put himself close to full fitness on Tuesday after hernia problems and said the team's defence needed to improve before the World Cup.
Defender Bocanegra underwent surgery about a month ago but is expected to lead the side in their opening Group C match against England on June 12.
The month-long World Cup kicks off in South Africa on June 11.
"I feel good, it was nice to get 75 minutes under my belt (against Turkey in a friendly on Saturday)," he said near their tournament base camp at Irene, between Pretoria and Johannesburg.
"I'm not far now, I just need to, myself, work on sharpening up the last five percent or so. I feel good."
The 31-year-old, who plays for French first division side Stade Rennes, said there was room for improvement in defence.
"The thing that sticks out to me is we need to be a bit better defensively," Bocanegra said.
Coach Bob Bradley said the team would draw inspiration from their form in the Confederations Cup in South Africa last year, when they took a 2-0 lead in the final before Brazil recovered to win 3-2.
"We learnt a lot last year and that includes making the final and playing well against Spain. That has given us confidence," he said.
He said the first match against England - who the US beat 1-0 in 1950 for their biggest World Cup upset - was a key game but the team's management was also keeping a close eye on the form of their other group opponents, Slovenia and Algeria.
"I think we have a tough group (but) of course so much attention has been put on the first match against England," Bradley said.
"It's a tremendous opportunity for us. The spotlight on that game is huge. It has already generated a great deal of interest in the United States."
