"I have spoken to him," Lambert told the club's official website. "The main thing is getting him back stronger. The football club will support him, which goes without saying. It will be a long rehab for him, and I think he knows that.
"The reality has probably sunk in now in terms of the World Cup tournament he will miss, but he is in a good generation so I don't think this will be the last tournament. It's six months. Some would come back quicker, others would take longer. Everyone heals differently."
The 23-year-old will undergo surgery today.