Coutinho has missed the Reds' past three matches due to a thigh a problem, but joined his national team for their upcoming friendlies in France and England.

However, the former Inter Milan maestro's chance of playing against Japan appear remote, with Rodrigo Lasmar telling Globo Esporte on Monday the player has yet to train with a ball.

"Coutinho had a muscle injury in the adductor of the left thigh," Lasmar said.

"He is in the final phase of recovery. We knew that he would not be fully fit, but we chose to make his final recovery with us.

"The possibility of him playing against Japan is remote, but we are working to make sure he's available against England.

"He may not be able to participate [against Japan]. If he can, he could be on the bench and play for a few minutes.

"But it's a small chance. Our focus is to get him back for the second game."

According to Globo Esporte, Coutinho trained in the gym on Monday with 10 other players -- Marcelo, Alex Sandro, Miranda, Thiago Silva, Casemiro, Fernandinho, Giuliano, Renato Augusto, Douglas Costa and Roberto Firmino.

But when it was time to take the field, the former Vasco da Gama star worked with physiotherapist Ricardo Sasaki.

Lasmar said: "Coutinho didn't feel anything, it was what we imagined, tomorrow [Tuesday] there will be physical work a little more intense. If everything goes well, he will begin working with the ball on Wednesday."