MIAMI – US national team head coach Jurgen Klinsmann is as mystified as anyone about Jozy Altidore’s recurring hamstring issues.

Toronto FC announced on Monday that Altidore will miss the next six-to-eight weeks due to a hamstring injury suffered in TFC’s 4-3 loss to Vancouver on Saturday, likely putting him out of this summer’s Copa América Centenario.

It’s the third-straight major tournament that Altidore will miss at least a portion of due to a hamstring injury; the 26-year-old striker missed nearly the entire 2014 World Cup after pulling his hamstring in the opener against Ghana and was sent home from last summer’s Gold Cup following the group stage due to what Klinsmann called fitness concerns following a hamstring injury he suffered earlier in 2015.

Speaking to reporters on Tuesday before the USMNT’s first training session of a pre-Copa camp at Barry University in South Florida, Klinsmann said it’ll be important to determine the cause – if there is one – of Altidore’s hamstring troubles.

“It’s definitely an issue that kind of follows him for quite awhile, and it’s something that we are all working hard on to get to the bottom of it, to find the cause for these hamstring injuries,” Klinsmann said. “Where does this really come from? Is it training-related? Is it environmentally-related? Is it lifestyle-related or a medical issue? Where does this come from? Hopefully, hopefully, the people work with him find the cause because that is the most important thing because, otherwise, he’s always questioning himself. He's always going to think, ‘what if something happens next time?’ Hopefully, we find that cause, find that problem sooner or later, hopefully sooner, and help him.

“It’s a huge bummer for all of us, especially for Jozy, because he had so much drive and ambition going towards the Copa América,” Klinsmann said. “He was preparing himself for the entire year, starting in January and he hoped to really peak in June for this very special tournament. Now, that message, I told him ‘you’ve got to put it behind you and keep going and stay positive and the next tournament is waiting for you.’ Obviously it’s a big blow for us and him personally, but there’s nothing we can do about it, unfortunately.”

Midfielder Alejandro Bedoya expressed a similar sentiment, lamenting the loss of Altidore scarcely two weeks before the Americans will open the Copa on June 3 against Colombia.

“It’s a blow of course,” Bedoya said. “He’s one of our key players and one of our best strikers. With every team, injuries happen. They’re part of the game. We’re just going to have to deal with it and move on. It’s an opportunity for other players to step in and prove their worth and help us out.

“Losing Jozy, not just as a team, but as a friend, it’s a big one.”

Now Klinsmann will be tasked with replacing Altidore, who is tied for third in USMNT history with 34 career international goals. He didn’t offer many specifics on Tuesday of how he’d go about doing that against Colombia, though likely candidates for increased minutes include recent Hamburg signee Bobby Wood, Seattle Sounders striker Jordan Morris and LA Galaxy attacker Gyasi Zardes.

None of those three players were in camp on Tuesday morning. Morris and Zardes will remain with their MLS clubs through the weekend, while Wood is scheduled to arrive in Miami later on Tuesday after taking care of responsibilities in Hamburg following Sunday’s announcement that he’d signed for the Bundesliga club.

Klinsmann must name his final 23-man roster for the Copa América by Friday. He’s currently leading a batch of a Europe- and Mexico-based players in a four-day “transition camp” in Miami ahead of Sunday’s friendly at Puerto Rico.

The players who make the USMNT’s final roster will travel from Puerto Rico to Dallas, where they’ll meet up with the MLS and Liga MX players named to the final squad but not currently with the team. The US will then play friendlies against Ecuador on May 25 in Dallas and against Bolivia on May 28 in Kansas City before taking on Colombia at Levi's Stadium in Santa Clara, California on June 3.