Maurizio Sarri believes Chelsea must improve in attack as they bid to secure Champions League qualification.

Head coach Sarri feels his team have tightened up defensively during a five-match unbeaten run in all competitions which has dragged him back from the brink of dismissal.

But the Blues remain the lowest scoring of the Premier League's top six clubs with 50 goals in 29 matches.

And, on the back of Thursday's 5-0 Europa League thrashing of Dynamo Kiev, Sarri wants more consistency in up front.

"Sometimes we've played with very good quality in the offensive phase, and sometimes not," he said.

"We started to defend in a very good way in the last month, I think.

"Now we need to start in the offensive phase to play every match with the same ideas.

"At the moment, we are not able to do this because, sometimes, we are without movement without the ball.

"Sometimes we didn't put the ball into the box very well, or attack the spaces behind the opponents' back-line very well. We need to have consistency on this."

Sarri faces a selection dilemma up front ahead of Sunday's trip to Everton.

First-choice centre-forward Gonzalo Higuain missed the midweek trip to Kiev due to illness, with back-up Olivier Giroud continuing his fine form in Europe by scoring a hat-trick.

Argentinian Higuain is expected to be fit to return at Goodison Park, meaning Europa League top scorer Giroud could be back on the bench.

"Higuain had a strong stomach ache with fever. It's not a serious problem." said Sarri.

"I think he will be able to play, but I don't know in what condition."

Chelsea required a last-gasp strike from Eden Hazard to rescue a point in last weekend's 1-1 draw at home to Wolves.

That result left the west London club three points behind fourth-placed Arsenal, albeit with a game in hand.

The Blues face another test of their top-four credentials on Merseyside.

Sarri believes Marco Silva's inconsistent Toffees, who secured a goalless draw at Stamford Bridge in November, have one of the strongest squads in the division.

"In my opinion, Everton, outside the top six, are the best team in the Premier League in terms of technical quality," said Sarri.

"So we have to play a very important match, and a very difficult game."

Sunday's match will also hold personal significance for Blues midfielder Ross Barkley.

England international Barkley, a boyhood Evertonian, returns to his former club for the first time since his £15million transfer in January 2018.

Sarri is unsure what kind of reception the 25-year-old will receive but hopes he is not verbally abused by home supporters.

"Usually I don't want to think about this kind of situation, if a player is an ex of another team or not. I don't like that," said Sarri.