Former Chelsea defender William Gallas says the answer to Romelu Lukaku's form problems is simply hard work.

Gallas, who won two Premier League titles and the League Cup with the Blues, says Lukaku should look to how record scorer and current Everton boss Frank Lampard approached things whenever he was struggling.

Gallas told The Sun: “[If he had a bad game] I remember Frank at the end of training always did more.

"Not just to score goals but to be fitter. To run more on the pitch.

"At training after one game, Frank wanted to work more and Jose [Mourinho] had to ask him to stop.

"Asked him to calm down to save his energy.

“But Frank wanted to do it to be fit and strong for the next game. Ready to attack and defend.

"When a striker doesn't score goals - and I know it can be difficult for them because the pressure is higher - you just have to work and work and it will come."

Lukaku also put himself further in the spotlight after an ill-advised interview drew huge criticism from fans and manager Thomas Tuchel.

The 28-year-old striker stated he was 'not happy' with his situation at Stamford Bridge in a December interview and was subsequently dropped.

"Unfortunately he has put himself under big pressure after he talked with the media," said Gallas.

“That means he has to have big shoulders and answer it on the pitch, it's a simple answer.

"If you are a striker at Chelsea, you have to score goals."