U.S. striker Jozy Altidore has told ESPN's Mike & Mike radio show he suffered a grade two hamstring tear against Ghana and would only have been available to start games if the Americans had reached the later stages of the World Cup.

Sunderland forward Altidore was substituted after suffering the injury early in the 2-1 win in his team's opening game.

It ruled him out of the remaining group matches against Germany and Portugal, but speaking ahead of Tuesday's round-of-16 match to Belgium -- which ended in a 2-1 defeat -- coach Jurgen Klinsmann had said he could be available.

In the event, Klinsmann named Altidore as a substitute but did not use him as the Americans tried to rescue the match in extra time -- and the player indicated that he would not really have been ready.

"I had a grade two tear in the Ghana game," he told the show. "The timetable to come back was realistically very late in the tournament."

"I honestly thought I was going to be able to help the team sooner rather than later but it just wasn't to be.

"It was a target of mine obviously when I first got injured to try and get back in that game but as it turned out when it got there it was still a bit early.

"It was a terrible moment for me because I've done it before in my other leg in 2011. That was a really bad one and left me out a month. I knew with this one it was similar and I was going to be out a while in terms of the tournament.

"I had a grade 2 tear in the Ghana game. The timetable to come back was realistically very late in the tourney" @JozyAltidore on hamstring - Mike & Mike (@MikeAndMike) July 3, 2014

"I was disappointed immediately because I know how big of an opportunity it is and how great it is to play in the World Cup so the first couple of days were really tough for me.

"I had such high expectations for my team and for myself. I was really excited about the opportunity of playing against some of the world's best players and making my mark but, at the same time, everything happens for a reason and I am committed to getting better and being a player on this team that can take us to the next level."

Altidore, 24, added that he and his fellow squad members had mixed feelings about their campaign, which saw them progress them progress through the so-called "group of death" but be sent home after the first knockout round.

"I think we performed well but, at the same time, if you go around and ask some of the guys, we definitely felt like we could have went a little further," he added. "Things happen, you know, circumstances change. We had some injuries and in the end, we just weren't able to get over that last hump in terms of Belgium."