Seven-times world champion Schumacher was due to replace the injured Felipe Massa but had to pull out with a neck problem, handing a golden opportunity to the team's experienced test driver.
"I have prepared myself to be ready under any circumstances just as I've been doing in previous years," Badoer told the team's website.
"I've been in this business for quite a while. After Felipe's accident [in Hungary last month] I intensified my program and I'm sure I won't have any problems."
Badoer started 49 races for Scuderia Italia, Minardi and Forti without scoring a point between 1993-99, his last competitive drive coming at the Japanese Grand Prix almost a decade ago.
However, the 38-year-old has been behind the wheel of Ferrari's existing F60 race car, something Schumacher could not do before he aborted his preparations for the European Grand Prix in Valencia on August 23 because of a ban on track testing during the season.
The Italian said he has mixed emotions.
"Since I was a child I've always wanted to race for Ferrari and now I've got the possibility to make this desire come true," said Badoer.
"I'm really sorry for Michael because I know how much he wanted to return. I'm saying that as his friend and his fan.
"I know he'll always be ready to give me advice."
Photograph: Reuters