Romelu Lukaku was accused of being unfit after Manchester United's draw with Chelsea .
The Belgian striker turned in a much-improved performance at Old Trafford although United failed to get the win they needed to return to the top four.
Lukaku played a key role in Juan Mata's opener and caused problems for Chelsea's defence throughout the clash.
But Sky Sports pundits Gary Neville and Alex Scott believe Lukaku still has fitness issues, having revealed in December that he had changed his diet in a bid to shed weight.
Speaking after the clash, Neville said: "You watch him for 25 minutes, he looks like a world-beater but you see him make one run and he looks knackered.
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"Football players should know their bodies inside out, you know when you can eat, when you should relax, the portion sizes.
"I am not sure how he hasn't corrected this problem.
"It is not a reflection on the sports science department at the club, something isn't right."
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Fellow pundit Scott was less forgiving and suggested the former Everton man must do something to improve his performances.
"I don't see how we can sit here and make excuses for him. That comes from the player," she added.
"He knows he is unfit. How is he allowed to get away from that as a professional footballer? By his teammates as well.
"As a professional footballer, you have to ask what he is doing away from the training ground and with his lifestyle."
Graeme Souness added: "I am amazed at a club like this he isn't under a stricter regime where he is bang on. He has to be managed."
The draw leaves United in sixth in the Premier League table and with it all to do to qualify for the Champions League with two games to go.
