Darwin Ceren, right, has been a key midfielder for Orlando City this season. Kim Klement/USA TODAY Sports

Orlando City say they are are "uncertain" about midfielder Darwin Ceren's knee injury as El Salvador won't reveal any information to them.

El Salvador captain Ceren was hurt in Friday's World Cup qualifier at Curacao, but despite repeated inquiries, Orlando City have yet to learn any details about the injury to their player.

"We are still uncertain as to Darwin's status," Orlando City coach Adrian Heath said. "We have called several times but have not been able to get any clear information as yet.

"At this stage he wants to remain with his [international] teammates for their second game, so we probably won't find out the full ramifications of his injury until we get him back and our doctors can look at him."

El Salvador play their home leg of qualifying against Curacao on Tuesday night, holding a 1-0 advantage from the first game.

Ceren, who previously played for Orlando City in the USL, is a key player in their midfield, starting all 21 games for which he's been available.

The expansion club has struggled when either he or Cristian Higuita have been out of the lineup, winning just twice in 13 games.

"Yes, they have been an important partnership for us," Heath said. "They definitely dovetail together well and give us a solid presence in midfield. I would certainly expect to pick both of them if fit."