Forward Jozy Altidore’s status for the knockout stage remains unclear, though he is making progress since straining his left hamstring in the first half of the Americans’ opening win against Ghana June 16.
Altidore ran at a good pace around the field without any signs of pain at Sao Paulo Futebol Clube on Friday and did some stretching on the sideline with the assistance of the training staff. He has run several times now without problems.
‘‘We are very optimistic,” said US coach Jurgen Klinsmann. “Every day is a big step forward with Jozy. It’s 11 days now and it’s looking better every day, so we are optimistic we have him being a part of the Belgium game.’’
US midfielder Jermaine Jones suffered a broken nose in Thursday’s game against Germany, but remains available to play in the Round of 16 against Belgium on Tuesday in Salvador, Brazil.
US Soccer spokesman Michael Kammarman said that Jones and fellow midfielder Alejandro Bedoya each were checked on the field for concussion symptoms during the 1-0 loss at Recife following their second-half collision, and three more times since then. There have been no issues for either player so far.
The US team arrived back to its Sao Paulo hotel at 11 p.m. Thursday, and Bedoya and Jones were examined again Friday morning.
Jones won’t wear a protective mask against Belgium.
‘‘I don’t remember really what happened,” said Jones. “I went for a header. The feeling was that it was broken.’’
Kammarman added that Jones’s injury doesn’t appear serious, as there is no visible bruising of the kind forward Clint Dempsey had when he broke his nose in the Ghana game.
‘‘He looks unaffected. You can’t even see any discoloration,’’ Kammarman said. ‘‘So it appears to be a minor fracture. He is fine, he’s available to play.’’
Attack is lacking
Klinsmann is eager for the US to create more chances against Belgium.
The Americans had just 72 attacks during three group-stage games, according to FIFA. That ranked 31st among the 32 teams, ahead of only Costa Rica’s 69.
The Americans were dead last in attacks from the left with 21 and tied for last with Iran with 29 from center. Right back Fabian Johnson seems to be providing the spark for most forays upfield, advancing more often than left back DaMarcus Beasley.
Midfielder Graham Zusi insists the approach and attitude must change if they are to reach the quarterfinals for the first time since 2002.
‘‘The first minutes of the game, impose yourself, step on their toes a bit, get in their face,’’ he said.
The US had 41 percent possession in its 2-1 win over Ghana, 48 percent in its 2-2 draw against Portugal, and 37 percent versus Germany. The Americans have been outshot, 54-27, in the three matches
Belgium, which is back in soccer’s showcase after a 12-year absence, have won three straight World Cup games for the first time. The Red Devils’ 136 attacks are seventh overall and nearly double the American total.
Despite a perfect record entering the second round, a recurring groin injury to center back Vincent Kompany has cast a pall over the Belgian campaign.
Any other player would have been relatively easy to replace. Yet in Kompany, Belgium coach Marc Wilmots has the essence of the qualities that got Belgium to the World Cup in the first place. Skills, power, vision, and leadership.
‘‘We will do all within our powers to make sure he comes back at 100 percent,’’ Wilmots said.
The coach said it was ‘‘impossible to say now’’ whether the Manchester City and Belgium captain would be ready to play against the physically imposing Americans on Tuesday.
Kompany strained his left groin in the last five minutes during the opening 2-1 victory against Algeria.
After a three-day layoff, he was excellent during a 1-0 victory over Russia but had to pull out after half an hour during the last training session ahead of Thursday’s 1-0 win over South Korea.
Ratings stay high
The US’ loss to Germany was the second-highest rated men’s World Cup match on ESPN’s networks despite the noon kickoff. The game received a 6.7 rating on ESPN and was seen by 10.77 million viewers, ESPN said. Viewers peaked at 12.06 million during the final half hour. The game trailed only last weekend’s 2-2 draw between the Americans and Portugal, which received a 9.6 rating and was seen by 18.22 million viewers on ESPN and 24.7 million overall, including Spanish-language coverage on Univision. The US’ 2-1 victory over Ghana got a 6.3 rating and 11.09 million viewers . . . After hundreds of fans flocked to City Hall Plaza to watch the US’ 1-0 loss to Germany Thursday, Mayor Martin J. Walsh announced he and the New England Revolution will host another watch party on Tuesday for the Americans’ Round of 16 bout against Belgium. The watch party will begin at 3:30, half an hour before the game begins.