James Rodriguez is reported to have missed training with Colombia on Saturday ahead of the World Cup last-16 meeting with England on Tuesday.
The 26-year-old, who was the top scorer at Brazil 2014, has been struggling with an apparent calf injury since the start of this summer's tournament in Russia.
Rodriguez left the field in the 31st minute of Colombia's 1-0 victory over Senegal on Thursday, but his injury has never been officially disclosed as the reason for the substitution.
According to The Independent, the Bayern Munich loanee is losing his race to be fit for the encounter against the Three Lions after sitting out training on Saturday.
Colombia, who will face England at Moscow's Otkrytiye Arena, have also not clarified the extent of Rodriguez's purported injury.
