The Belgium international scored five times in five games to make a brilliant start to the 2018-19 Premier League season.
Hazard scored his second-ever hat-trick for the Blues in a 4-1 win against Cardiff City at Stamford Bridge earlier this month.
The 27-year-old, though, failed to get on the score sheet in Chelsea FC’s goalless draw with West Ham in the derby at the London Stadium.
The Chelsea FC number 10 found himself in deeper position to limit his ability to have an impact on the London derby at the weekend.
Former Blues winger Nevin explained why Hazard needs to be in more advanced positions.
“We know Eden Hazard is at his very best coming off the left-hand side, in the last third, i.e. as a left winger in essence,” Nevin told Chelsea FC’s website.
“But what if the team lines up as a 3-5-2 as we did sometimes last season, there is no left winger as such in that line-up. Eden adapted and played in a slightly different role, often as a secondary striker, even though it might not have suited him absolutely perfectly.”
He added: “Eden not getting enough good service in the last third was maybe the most important part of the game at the weekend. If he is too deep in his own half too often when he receives the ball I am always quite concerned. He still beats players for fun but the effect is much more positive the nearer he is to the opposition goal.”
Sarri took over the reins from Antonio Conte in the summer following Chelsea FC’s fifth-placed finish in the Premier League table last term.
The Blues were 1-0 winners against Greek side PAOK in their Europa League group stage opener last week.
The west London side will make the long trip to Anfield in their League Cup third-round clash on Wednesday night.
Chelsea FC will welcome Liverpool FC to Stamford Bridge in the Premier League on Saturday evening.
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