Fabregas, already nursing a sore shoulder, was struck by a ball in training on Monday that hit the fibula bone he cracked playing for Arsenal in the Champions League at the end of March.
An X-ray on Tuesday morning showed no bone damage and Del Bosque said Fabregas had trained well in the evening in Durban, where Spain play Germany in a repeat of the Euro 2008 final.
"We were worried yesterday because he took a knock in the same place as his injury," Del Bosque told a news conference at the seaside city's Moses Mabhida Stadium.
"I think he'll be able to play, depending on further tests."
Fabregas has yet to start in the tournament but came on as a second-half substitute for striker Fernando Torres in Spain's 1-0 quarter-final win over Paraguay on Saturday.
He damaged his shoulder in that game but said he was prepared to have a pain-killing injection on it so he could play against the Germans if needed.
Fabregas helped Spain win the European Championship in Vienna, when they beat Germany 1-0 in the showpiece match.
