USA coach Jurgen Klinsmann is "optimistic" that striker Jozy Altidore will return from injury to play against Belgium in the FIFA World Cup™ Round of 16.

The German said Altidore, who trained separately from the squad with some light jogging today, was improving daily from a hamstring injury suffered in their opening game, a 2-1 win over Ghana.

USA qualified for the knockout stages despite Thursday's 1-0 loss to Germany and they will now play Belgium in Salvador on Tuesday.

"We are very optimistic. Every day is a big step forward with Jozy," Klinsmann told reporters at USA's base camp in Sao Paulo.

"It's 11 days now and it's looking better every day so we're optimistic to have him being part of the Belgium game."