The striker was substituted early in the Champions League final after suffering a torn hamstring but could still make Spain's World Cup team.
The Atletico Madrid forward tore his hamstring in his side's Champions League final defeat to Real Madrid, which has resulted in Del Bosque delaying finalizing his 23-man squad — and he may even wait until the FIFA deadline June 2.Del Bosque had earlier conceded he "wasn't sure" whether the 25-year-old would be fit for Brazil but he has now revealed that the striker and midfielder Jesus Navas are showing encouraging signs in their efforts to return to fitness.
"It looks promising. On Friday they will have a scan. If it's good, we will make a decision on Saturday morning," he said during a news conference Friday.
Costa was the subject of much controversy when he opted to play for Spain rather than Brazil. He made two friendly appearances for the Selecao in 2013 before making his international debut for Del Bosque's men against Italy in March.
Costa will not feature for Spain in Friday's friendly against Bolivia, meaning Fernando Torres is in line to stake his claim to a World Cup spot.