Leicester City manager Claudio Ranieri believes his side face a tough task to penetrate Manchester United's defensive lines when they lock horns on Saturday.
Surprise Premier League leaders Leicester are the division's most prolific team so far this season with 28 goals in 13 games, although their record of 20 conceded is as much as anyone outside the bottom six.
United have excelled defensively in conceding just nine times so far, keeping eight clean sheets in the process, although possibly to the detriment of their usual attacking style, with Louis van Gaal's men coming under criticism from some quarters.
"Manchester United's defensive line is fantastic," Ranieri said at a news conference.
"They defend like a unit and it's difficult to break their lines."
Ranieri will be hoping Jamie Vardy can continue his goalscoring run in the Premier League as the striker aims to break Ruud van Nistelrooy's record of netting in 10 consecutive games, having equalled the Dutchman in last week's 3-0 win over Newcastle United.
"Vardy is a champion. For me he's a champion because he thinks more about the team than himself," Ranieri added.
"I hope for Jamie and for the fans that he breaks the record."
Vardy currently tops the Premier League goalscoring charts with 13, four clear of Everton striker Romelu Lukaku.
