Carlo Ancelotti had signed James Rodriguez, Allan, and Abdoulaye Doucouré into the team and they now look rejuvenated, but still leaking in few goals.
Calvert-Lewin, whose form earned him an England call up, believes the club has made a vital shift on and off the pitch, leading to the club’s superb start to the new season.
Everton has now won their first four Premier League games for the first time in the modern era.
The 23-year-old striker opened the scoring on Saturday in a 4-2 win over Brighton. He is now the first Toffees player to score in the club’s first four Premier League games of a campaign. He has scored nine goals so far this season from just six games.
“There’s been a mentality shift and a momentum shift around the place and that has been a big catalyst [for our form], as well bringing in the new players and the quality they’ve got.
“What they’ve added to the team has been crucial. We have gelled really well and the system we play suits us.
“In the second half [against Brighton] we didn’t play that well, to be honest. But we scored goals in the second half and the best teams win when they are not always on top. We dug in and limited their chances.
“We started the game well, though. On the whole, I think it was a solid performance again. We are feeling confident, creating chances and scoring goals,” Calvert-Lewin told Everton’s website after the Brighton win.
Is Everton going for the title?
The last time Everton won each of their opening four games in a top-flight season was the 1969-70 season. They went on to win the title.
Although Everton is not a fully compact team yet, anything is possible in the Premier League if a determined Leicester City can shock the big boys and took the title.
Also in good form is James Rodriguez. The Colombian stole the show by scoring a brace and assisted Yerry Mina’s header for the Toffees’ second goal.
While describing the playmaker as a top player, Calvert-Lewin said he is enjoying their partnership.
“James is a top player. “You can see when he gets on the ball, the quality he has got. He draws people in and opens space up for other players on the pitch.
“As a centre-forward, he creates chances and that’s all you can hope for.”
Speaking on the impact of Mina, who also netted his fourth Everton goal, Calvert-Lewin lauded the Colombian center-back and led a Macarena dance to celebrate his effort.
“It’s just Yerry, isn’t it?!
“He enjoys dancing and celebrating and enjoys his football. The energy he brings to the team is contagious. He’s great for the team,” Calvert Lewin said: