Colombia midfielder James Rodriguez will undergo an MRI scan at the weekend to determine whether he can play a part in his side's World Cup tie against England next Tuesday.
The Bayern Munich loanee is suffering from a calf problem that has restricted him to just one full 90-minute outing so far in Russia.
James bagged a couple of assists in that 3-0 win against Poland, highlighting his importance to this Colombia side, and manager Jose Pekerman admits that he is "extremely concerned" that his star man will be absent for the last-16 clash.
A scan has been arranged for the next 48 hours, with the South Americans expected to have a better indication of the 26-year-old's fitness by the end of Sunday.
2014 Golden Boot winner James missed training on Friday, a day after being replaced with half an hour played in the 1-0 win over Senegal.