Leicester City will feel like they are playing down a man all season with the departure of N'Golo Kante, manager Claudio Ranieri says.
Kante led the Premier League in both tackles and pass interceptions last season while completing 81 percent of his passes as he played a huge part in Leicester's fairytale title run.
But the Frenchman has moved on to Chelsea this summer, and Ranieri said Kante would be impossible to replace with just one midfielder.
"There will be a big difference," the manager told several English newspapers. "If Chelsea bought Kante, it's because he played as two players last season. The referee counted 11 but we were 12.
"Now everybody must understand that there is no Kante so we have to be more close, more attentive. We have to think different and close space quicker. We must be smarter."
Leicester's title win means they will have some extra fixtures this season -- starting with Sunday's Community Shield against Manchester United -- before the huge test of the Champions League.
Ranieri managed to win the Premier League by using just 23 players last season, but he acknowledged that he would need a few more for the upcoming campaign.
"For this reason I asked my owner to have a minimum of 22 players with the same level because I have to change something during the season," Ranieri said.
"It's not so difficult for the fitness to manage 16 or 17 more matches, it's mentally. It is difficult to recharge the batteries for a team that is playing in it for the first time. The big teams are used to playing in it, for us it is new.
And despite Leicester employing psychologist Ken Way, Ranieri said he was happy to help his players through the mental challenges to come.
"I am the psychologist," he said. "When you are young maybe you need somebody who can help you. But now you are a man and in life you need to be strong.
"Once I had a psychologist who told me when we played at home there was a big elephant in the dressing room. I said, 'I never saw this big elephant.' He said, 'We have problem, but not away.'
"I said, 'But you can understand tactically that when we are at home the other team stays all together behind the lines and we have to find a way through?'
"Then, when we won the title, I said, 'Where is the elephant?' Maybe I will play the elephant in goal!'"