The most expensive English player did not play against Bulgaria in the Euro 2012 qualifier that England won 3-0 on Friday but has been training well and could play a role against Wales at Wembley on Tuesday.
"His style of life is a problem, if it is not good," Capello told a news conference when asked about the 22-year-old.
"He needs to be careful because he is an important player not only for the England team but also for Liverpool," Capello told a news conference. "I think he understands what he needs to do."
"I think if he wants to be a good player and a good sportsman, he needs to drink less than the normal," said Capello.
"It's a private message," he added when asked what he had told the player. "I spoke with him and it was a private discussion.
"He understands a lot, he is young and we need to help him and speak with him because he is a really important player."
