Colombia manager Jose Pekerman said he remained "optimistic" about James Rodriguez's ability to carry on at the 2016 Copa America after leaving his team's 2-0 win versus the United States with an apparent shoulder injury.
Rodriguez, 24, played a crucial role in Colombia's Copa-opening victory, converting from the penalty spot at the end of the first half to double Los Cafeteros' lead before half-time.
However, the Real Madrid midfielder fell awkwardly in the second half and got up holding his left shoulder and was substituted shortly after by Pekerman in the 73rd minute.
"I want to be optimistic," Pekerman said. "James is very important for Colombia. We also know he has a lot of desire to play. But I think the medical professionals know to what extent he'll be running a risk. We cannot take a fast decision.
"I don't want to think of the negative. We will see, we will be optimistic, and we hope that James will recover well and we will have him on the field."
Pekerman also had praise for his opponents, acknowledging the continued progress of the American team since their campaign at the 2014 World Cup.
"I won't say this was a perfect example of their ability, but the U.S. team has evolved from what we saw in Brazil."
Colombia's next match is on Tuesday, June 7, against Paraguay at the Rose Bowl in Pasadena, California. The U.S. returns to action in Chicago on the same day against Costa Rica at 8 p.m. ET.
ESPN FC writer Doug McIntyre contributed to this report.