Jamie Vardy started on the bench for Leicester City's 3-1 win over Crystal Palace.
Vardy has now not scored in his last 10 appearances for club and country after coming on as a second-half substitute.
"It's normal because we have to play so many matches. All the matches are important and when you see Okazaki and Musa in training I have to put them on the pitch," said Ranieri.
"It wasn't (because) of injury. If he was injured he wouldn't have come with me on the bench. I don't know if he needed a rest, but if I don't have Shinji, Musa and (Leonardo) Ulloa maybe I have to play him, but when you have some good players it's right to have a rest."