The Bolton player continued his comeback from a fractured fibula as he completed 90 minutes in the USA's 4-2 defeat by the Czech Republic in Connecticut last night.
Holden, 22, suffered the injury in a tackle with Nigel de Jong during the USA's friendly against Holland in March and returned to action on the last day of the Premier League campaign when he played 24 minutes of Bolton's 2-1 win over Birmingham.
He made an immediate impact on his return to the international side, sending in a dangerous free-kick from the left that Petr Cech failed to deal with and led to Maurice Edu's opening goal.
And though the USA lost their penultimate game on home soil before heading to South Africa, Holden revealed he was happy with the way his fitness was progressing.
"It was a big step forward for me," Holden said of his appearance against the Czechs. "With my rehab it was always important for me to get a game and I got that with Bolton at the end of the season as a substitute. It's just a case of getting more games under my belt and improving my fitness. I don't think I'm far away, to be honest."
Holden admitted he had begun to fade with about 15 minutes to go at Renstchler Field. "This was my first 90 minutes in probably three and a half months and at the end of the second half my legs got a little bit tired. I was a little lackadaisical on set pieces but that's something I'll focus more on.
"I started to tire in maybe the 75th minute and on a hot night when the Czechs were passing the ball around we were doing a lot of running. I'll have heavy legs now but I'm pretty close to match fitness."
With USA coach Bob Bradley set to name his final 23-man squad for the finals on Wednesday, he rested many first-choice players including Tim Howard, Clint Dempsey, Jozy Altidore, Landon Donovan and captain Carlos Bocanegra against Czech Republic and the game was a nervous affair for many players on the fringes of selection.
Holden and Rangers duo DaMarcus Beasley and Maurice Edu impressed at times, all playing in a variety of positions as they demonstrated their versatility.
"I think it's one of my strengths," said Holden, who played across the midfield. "I'm comfortable playing either in the middle or out wide and I think it's going to help me going forward. Bob knows I'm comfortable with it too, and that helps as well."
Edu not only grabbed his first international goal but also dropped back from his holding midfield role to central defence late in the second half. "It's a position I played at the Olympics so it is familiar," Edu said. "In training I played a little bit back there and in the middle as well. In the game I got a little bit tired but I felt pretty comfortable back there and if need be I'd play back there."
Beasley had a busy 45 minutes in the first half, starting on the left side of midfield, switching at times to the right and dropping to left-back to help an under-pressure Jonathan Bornstein before both were subbed at half-time.
"It's been a good camp for DaMarcus," Bradley said. "He's shown his team-mates again there is renewed commitment to everything and I think that's what he showed on the field."
Beasley, who won his 92nd cap having worked his way back into the USA reckoning, said: "I've always been committed to the national team but I had a rough time when my form went down and my confidence went down as well.
"I've always tried to play my best for my country. It didn't happen that way and I got down on myself. All I asked for was a chance with my club and now that I'm getting back into playing and training regularly, I feel like I'm back to being myself."