The 33-year-old Bocanegra, the American captain since 2007, has lost his starting job with Racing Santander, a Spanish second-division team on its fourth coach of the season. Bocanegra, on loan from Glasgow Rangers, and has not appeared in a game since Feb. 2.
Klinsmann said he's had several conversations with Bocanegra and expects him to switch clubs at the end of the season.
“He's simply not playing. He's not getting any minutes ... so he has no flow. He has no rhythm, and he understands that situation,” Klinsmann said.
“Carlos is still in our picture. This is not the end of his national-team career, but he understands that he is right now behind other players.”
With Bocanegra dropped after 110 international appearances and Howard recovering after breaking two bones in his back on Feb. 26, Michael Bradley and Jermaine Jones become the leading candidates to take over as captain.
Klinsmann planned to announce his choice Tuesday, after telling the team.
The U.S., which lost 2-1 at Honduras last month in its opener of the 10-game final round, plays Costa Rica on Friday at Commerce City, Colo., then is at Mexico City on March 26. The group also includes Panama and Jamaica, and the top three teams qualify for next year's tournament in Brazil, with the fourth-place finisher advancing to a playoff.
“Every home game in a hexagonal is a must-win situation,” Klinsmann said.
Among those missing from the 23-man roster are Edgar Castillo (triple facial fracture March 2), Chandler (injured hamstring Saturday), Steve Cherundolo (knee surgery Feb. 6), Johnson (sidelined by hip injury since March 3),
Jonathan Spector (injured ankle Saturday), Jose Torres (injured hamstring Saturday) and Williams (stomach virus).
Brad Guzan takes over in goal in his first qualifying appearance since 2009. The new central defense tandem of Omar Gonzalez and Geoff Cameron was shaky in the Honduras loss on Feb. 6, and the Americans have no experienced options at outside back.
“Definitely a challenge,” Klinsmann said.
Just six defenders are on the roster, with Cameron and Gonzalez joined by Tony Beltran, Matt Besler, Clarence Goodson and Justin Morrow. Cameron has played right back for Stoke, Fort Wayne's DaMarcus Beasley has played left back at times and Maurice Edu played in central defense in last summer's exhibition win at Mexico, where the Americans had been 0-23-1 against El Tri in 75 years.
Beltran, Besler and Morrow made their national team debuts during a January exhibition against Canada.
In addition, Landon Donovan remains on an extended offseason break before rejoining the Los Angeles Galaxy in late March.
“If he will be become part of our plans again, that depends on how he comes back and how I look at the whole picture and how I look at the development of this team,” Klinsmann said. “The door is always open.”
Clint Dempsey, who has been sidelined by a calf strain since Feb. 21, returned Sunday to play the second half in Tottenham's 1-0 loss to Fulham. Bradley has struggled for playing time of late for Roma and has not gone a full 90 minutes since Feb. 24, three weeks after Aurelio Andreazzoli replaced coach Zdenek Zeman.
“I'm just curious to hear his side of it,” Klinsmann said.
Beasley, a 30-year-old midfielder who is a veteran of three World Cups, rejoins the team for the first time since the Mexico exhibition. Midfielder Brek Shea also was picked despite being limited to two appearances, both as a substitute, since joining Stoke in January.
“We want to see where he is right now,” Klinsmann said. “We are pretty confident that he can add another element to our group here.”