Real Madrid have been angered after Eden Hazard was selected for Belgium's Nations League games only to be left out for both contests.
Los Blancos had asked that both Hazard and Thibaut Courtois be left out of the squad as they prepare for the new season.
But Roberto Martinez opted to pick both players for their games with Denmark and Iceland.
Courtois returned to Spain on Friday, but Hazard remained with the squad despite not appearing at all which has not gone down well in the Spanish capital, reports AS.
The 29-year-old moved to the Bernabeu last summer in a mega money deal but failed to match expectations.
Injuries played their part, although Martinez revealed that the winger is fit enough to play with his omission down to easing him in gradually.
"Medically he's absolutely fine, it's just a question of being careful when bringing him back in," Martinez told Cadena Cope.
"He's still not 100 percent and hasn't been able to take part in group training at his club. We're going to be very careful and not run any kind of risk.
"Eden needed to work on his own to be able to start pre-season without any risks. He's not ready to play 90 minutes."
Martinez had previously stated that Hazard would appear in at least one of their games.
The former Chelsea man almost chose not to be involved during the international round of games - a decision made by club team-mates Luka Modirc and Martin Odegaard.
Hazard didn't even come out to warm-up before Belgium's 5-1 win over Iceland on Tuesday night.
Madrid, who recently won La Liga for the first time in three years, will open their season against Real Sociedad on September 20.
