Gerrard caused headlines yesterday after leaving England training early in the morning. He headed to the dressing room after starting in a 10-v-10 practice match.
"We spoke after the game against Ukraine and Steven thought he'd be fit, perhaps for this game," Capello said. "He practised with us but, after 10 minutes, he felt it.
"It's not a big problem. He'll be fit in two or three days but their manager will decide as they have the Champions League afterwards."
Eager to avoid a row with Liverpool, Capello added: "He decided to stay here. We asked him what he thought, and he thought he'd be fit. If he'd not been fit, he'd have gone home."