Tottenham Hotspur boss Mauricio Pochettino says his players have to be focused when they take on Southampton at White Hart Lane.
Ronald Koeman's side enjoyed a brilliant start to the season as they lie second in the table and Pochettino, who coached the Saints last season, knows they can be a very dangerous team.
"They are in a good moment, a good period in the Premier League and they have a strong team," Pochettino told the club's official website.
"It's a tough game for us on Sunday.
"They've had a very good start of the season, they are at the top of the table, they are playing well and we expect a very tough game.
"We want to show the same performance at White Hart Lane on Sunday. That's important for us."