Joe Hart has been ruled out of the Manchester City side to face Saints tomorrow, but David Silva is available again.

City slipped to third after their 4-1 hammering by Liverpool but with top two Leicester and Manchester United playing each other, they have a chance to make up ground this weekend.

The loss of Hart, who has been in fine form this season, is undoubtedly a blow but Pellegrini has confidence in his replacement Willy Caballero.

Pellegrini said: "I think he will be around 10 days out. Fortunately it is not a very serious injury but it is a muscle injury so it is important for him to recover well.

"But I never complain about players who are injured. That is why we have a squad. We lost Joe in a very good moment but it is what happens. I trust a lot in Willy Caballero. I am sure he will have a good performance in these games."

City have been troubled greatly by injuries in recent weeks with Hart joining captain Vincent Kompany, Eliaquim Mangala, Pablo Zabaleta and Samir Nasri on the sidelines.

But the return of Silva provides a big lift after a nine-game absence with an ankle problem while the availability of Bony increases attacking options at a time when Sergio Aguero still lacks match-sharpness.

Pellegrini said: "David is a very important player, the same as Kun - one of the players that is very difficult to replace. I hope both of them can recover."

With a 0-0 draw at Aston Villa earlier this month, City have actually gone three games without a win but Pellegrini is not overly concerned about form yet.

He said: "Maybe one defeat in this club is a crisis for this club, in the media. Of course you worry when you don't win two games in a row but if you take an overall view I think we are having a very good season."

Southampton are likely to provide another strong test having not yet lost away from home in the Premier :League this season.

Pellegrini said: "In Premier League you never know which team will win against the other. You see Liverpool come here and beat us but Crystal Palace went to Liverpool and beat them, and after that Sunderland beat Crystal Palace.

"Southampton are having a good season. They have good players and we need to play in a high performance if we want to win."

The absence of Hart means third-choice Richard Wright, the 38-year-old former England international, who played seven times for Saints during a loan spell, will be on the City bench. He last played in the top flight for Everton nine years ago and has not played a competitive game at any level since appearing for Ipswich in 2011.