Manchester City boss Manuel Pellegrini says Southampton's position in the table should not be a surprise.
The Saints are currently second in the table, six points from leaders Chelsea, and the Chilean knows his players will have a tough game when they face Ronald Koeman's side on Sunday afternoon.
"They are a good team with very good players and they're playing very well," Pellegrini said.
"It's no surprise they are where they are. Ronald Koeman has lost four or five players but they are still a good team and that's a merit to him. It will be a tough game."
Asked about Sergio Aguero making a difference for the Citizens, Pellegrini said: "Sergio is a top player.
"He's a very important striker in the Premier League and we're very glad to have him.
"I am always asking and demanding that he tries to be the best player because he has all the conditions to do that.
"I am sure he is in the top five [players in the world]. I don't think he is better than Cristiano [Ronaldo] or [Lionel] Messi, but he must be very near because he has all the conditions to do it.
When he plays, it makes a difference."