The 31-year-old Liverpool player is touch and go as to whether he will be fit enough to face Bulgaria and Wales in early September after undergoing a groin operation in the spring.
"I read this and it was not good news," Capello told Sky Sports News.
"I think also, Steven Gerrard is a very important player for us and also for Liverpool. It's been a long time this injury.
"I hope he will return quickly because he's one of the players that makes the difference on the pitch."
Gerrard has 89 international caps to his name after making his debut against Ukraine 11 years ago.