Former Wales assistant coach Raymond Verheijen has warned England and Tottenham Hotspur against "exhausting" Harry Kane.
The 21-year-old is the joint-top scorer in the Premier League this season, and scored just over a minute into his international debut in England's 4-0 win over Lithuania last night.
The Dutchman told talkSPORT: "Unfortunately all these youth players are thrown in at the deep end. Not only does the speed go up, but the volume does at the same time and basically you are exhausting these young kids.
"The coaches need to reduce the volume in the beginning so they can keep up with the speed and then gradually increase the volume in training.
"[Kane's] body needs time and you cannot solve that with conditioning, he firstly needs time to adapt to play at this level and then secondly to get used to playing two or three times a week."
England play Italy in a friendly on Tuesday.
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