Andrei Shevchenko has put his faltering start with Chelsea down to World Cup fatigue.
The Ukrainian international has failed to hit the heights expected of him so far in England, with just two goals to his name since a £30 million switch from Milan over the summer.
Shevchenko's dry spell has seen the feared hit-man become the subject of criticism but his club manager has staunchly defended his most expensive acquisition of the summer.
Now Shevchenko, who is a major doubt for Ukraine's Euro 2008 qualifier with Italy on Saturday due to a fever, says he arrived in England tired after reaching the quarter finals of the World Cup with his country.
"You get high points and low points in your life," said Shevchenko
"In addition when I arrived I was tired from playing at the World Cup. "And right now, I feel really bad.
"I have been in bed with a high fever that has reached 39.4 degrees and even speaking is painful for me.
"The doctors told me I have picked up a viral infection.
"I began having problems on Tuesday when I arrived in Kiev for the Ukraine team's get-together.
"I don't yet know whether I will miss the game against Italy as the doctors won't commit themselves, but my fever has continued to rise."
International colleague and former Dynamo Kiev strike partner Sergei Rebrov has backed Shevchenko to shine in England however, after his own spell with Tottenham Hotspur was branded a failure.
"It takes time to adapt to what is required in England but Chelsea will soon see Andrei scoring goals regularly, just like he always has," said Rebrov.
"How can anyone have doubts about one of the greatest strikers to have played in Europe in the last ten years?
"Andrei has scored goals wherever he has been against all opposition and he will have the same success in England.
"There were times when I found it very difficult after arriving in England and being so far away from what you are used to can be a struggle.
"That is when you need the support of your coach to help you and Jose Mourinho backs Andrei 100 percent."
Shevchenko was also the subject of criticism in Italy as he appeared to kiss Chelsea's badge after scoring on his debut in the Community Shield, an act that angered supporters of his former side Milan.
"With the story of the kiss to Chelsea's jersey someone wanted to portray me as I am not," Shevchenko told Corriere della Sera. "I'm not a betrayer.
"Each of us takes the decisions in life he considers most right and these decisions must be respected.
"I have earned the respect of supporters by working on the pitch and the only jersey I have kissed and the only one I'll continue kissing is the one of my national team.
"My story with Milan and with Milan as a city is ended as a football situation, but for the rest it will not end."
The Ukrainian international has failed to hit the heights expected of him so far in England, with just two goals to his name since a £30 million switch from Milan over the summer.
Shevchenko's dry spell has seen the feared hit-man become the subject of criticism but his club manager has staunchly defended his most expensive acquisition of the summer.
Now Shevchenko, who is a major doubt for Ukraine's Euro 2008 qualifier with Italy on Saturday due to a fever, says he arrived in England tired after reaching the quarter finals of the World Cup with his country.
"You get high points and low points in your life," said Shevchenko
"In addition when I arrived I was tired from playing at the World Cup. "And right now, I feel really bad.
"I have been in bed with a high fever that has reached 39.4 degrees and even speaking is painful for me.
"The doctors told me I have picked up a viral infection.
"I began having problems on Tuesday when I arrived in Kiev for the Ukraine team's get-together.
"I don't yet know whether I will miss the game against Italy as the doctors won't commit themselves, but my fever has continued to rise."
International colleague and former Dynamo Kiev strike partner Sergei Rebrov has backed Shevchenko to shine in England however, after his own spell with Tottenham Hotspur was branded a failure.
"It takes time to adapt to what is required in England but Chelsea will soon see Andrei scoring goals regularly, just like he always has," said Rebrov.
"How can anyone have doubts about one of the greatest strikers to have played in Europe in the last ten years?
"Andrei has scored goals wherever he has been against all opposition and he will have the same success in England.
"There were times when I found it very difficult after arriving in England and being so far away from what you are used to can be a struggle.
"That is when you need the support of your coach to help you and Jose Mourinho backs Andrei 100 percent."
Shevchenko was also the subject of criticism in Italy as he appeared to kiss Chelsea's badge after scoring on his debut in the Community Shield, an act that angered supporters of his former side Milan.
"With the story of the kiss to Chelsea's jersey someone wanted to portray me as I am not," Shevchenko told Corriere della Sera. "I'm not a betrayer.
"Each of us takes the decisions in life he considers most right and these decisions must be respected.
"I have earned the respect of supporters by working on the pitch and the only jersey I have kissed and the only one I'll continue kissing is the one of my national team.
"My story with Milan and with Milan as a city is ended as a football situation, but for the rest it will not end."