PRAGUE–Jozy Altidore, finally recovered from the injury that cut short his World Cup after just 22 minutes, says he’s ready to leave it all on the pitch against the Czech Republic on Wednesday in the U.S. national team’s first match since Brazil.

“I’m going to give it everything I have,” Altidore told American Soccer Now after the U.S. squad put in its first training session under rainy skies in Prague. The Czech Republic team will use the friendly match to prep for the opening game of its campaign to qualify for Euro 2016 against the Netherlands next week.

“Playing for the national team is not a courtesy call, it’s not secondary to anything,” Altidore said. “I want to go out there and put in a good performance and help out these young guys who are going to get their first cap.”

Jurgen Klinsmann put his 21 players through their paces on a gloomy day at the Czech Football Federation’s training grounds atop Strahov Hill, a stone’s throw from the medieval castle that towers over Prague. The mostly European-based roster includes a host of young talents eyeing their first cap, including 18-year-old Emerson Hyndman of Fulham and Stanford University’s Jordan Morris, the first college player called up to the national team since Chris Albright in 1999.

A surprise presence in Prague was Leipzig striker Terrence Boyd, who spent the afternoon session jogging around the track as part of his recovery from a torn knee ligament.

Altidore also knows all about injury.

In the 22nd minute of America’s first game of the World Cup in Natal, Altidore raced on to a long ball from Michael Bradley before pulling up and crumpling to the ground as he grabbed his left hamstring. It was a massive blow, but he said he’s moved on.

“It was tough, it was difficult,” Altidore said. “But this is life, this is sports. The biggest thing I can do now is focus on now, on today, and try to be better than I was in the summer and try to be healthier and stronger.”

He will need to be. Altidore, who has yet to start this season for his English club Sunderland, struggled last year when he scored only one goal in 39 appearances for the Premier League squad after moving from AZ Alkmaar in the Netherlands, where he tallied 39 times in 67 matches.

This season, Altidore said he must be far more active in taking on defenders.

“I’m feeling OK now but I’m still getting up to speed from my injury,” he said. “I just need to be more aggressive, to try to do things on my end, try to be more aggressive and try to be a guy they can depend on.”

But on the final day before the transfer window closes, Altidore suggested that his scoring touch could be aided by an injection of fresh talent at Sunderland.

“We need some more quality, I think anyone will tell you that,” he said. “We’re still missing some pieces at Sunderland but hopefully, you know, we can make some good signings and have a better season than last year.” Shortly after speaking to ASN, Sunderland signed Argentinean attacking midfielder Ricky Alvarez on a season-long lone from Inter Milan, according to U.K. media reports.

Asked by a Czech reporter whether America’s run to the round of 16 in Brazil proved that U.S. soccer has broken through to another level, Altidore said it was “definitely a step forward.”

At the same time, he said, much remains to be done.

“It starts for us again on Wednesday,” the striker said. “It’s the start of the four-year cycle. It’s the first opportunity to show the manager that you want to be a part of Copa America in two years and then the World Cup. It’s a big opportunity for everybody and you have to put your best foot forward.”

Jeffrey Donovan is a veteran journalist based in Prague, Czech Republic. Follow him on Twitter.