Ecuador coach Reinaldo Rueda remains cautious on the fitness of midfielder Christian Noboa ahead of his country's FIFA World Cup opener.
Noboa sustained an injury to his right leg early in the second half of last week's 2-2 friendly draw with England in Miami.
On Tuesday, he was restricted to a light workout ahead of Sunday's Group E clash with Switzerland in Brasilia.
"Let's be careful with our decision regarding Christian," Rueda is quoted as saying in El Comercio, having already lost Noboa's fellow midfielder Segundo Castillo to a knee problem.
Chivas USA's Oswaldo Minda was confirmed as Castillo's replacement in the Ecuador squad on Tuesday.
Noboa respects his coach's reluctance to make a firm statement on his availability, but the Dynamo Moscow man is somewhat more upbeat.
He said: "(Whether I play) depends on the coach. I'm excited and want to play."
Noboa is set to be assessed by team doctors on Wednesday, while his team-mates will take part in an afternoon friendly match against local fourth-tier team Ceramica.
The game provides a chance for Minda to press his claims after joining up with the squad.