Injured Ba out of Senegal game
The Senegal striker suffered a broken nose in last Saturday's loss at his former club Newcastle and his withdrawal follows that of Czech Republic goalkeeper Cech, who has a finger injury.
A story on chelseafc.com read: "The Senegal Football Federation have announced that Demba Ba has withdrawn from the squad ahead of their game against Guinea, after suffering a broken nose during Saturday's 3-2 defeat against Newcastle United."
Scolari decided to keep the 25-year-old in his squad for the game at Wembley but he will not play unless he passes a fitness test, the Brazil manager said.
"Regarding David Luiz he will (have to) pass another exam with our physios, then we will decide whether he will play or not," Scolari told a press conference at Wembley.
"We will not take any risks with him."