Manchester City boss Manuel Pellegrini believes striker Sergio Aguero has the potential to become the best player in the world.

Aguero’s superb start to the season, which as seen him score 11 goals in as many games, including four against Tottenham last weekend, has reignited debate over his standing in the world game.

A year ago comparisons with the likes of Cristiano Ronaldo and Lionel Messi were common but injuries then hampered Aguero throughout the second half of last season. Those problems, which also affected the Argentina international at the World Cup, now seem behind him and he appears close to his blistering best.

But Pellegrini expects the 26-year-old to get even better and eventually surpass the levels of those currently regarded as the best.

Pellegrini said: “Sergio is a young player, he has a lot of years to improve – three or four years more than other players. It just depends on what he wants to do in the future. I think he has all the conditions to do that.

“I don’t think it is the best I have seen from Sergio. I was always sure he would return to his normal performance but I think he can get even better.”

Another key member of the City side in recent weeks has been Frank Lampard, who has made an unexpectedly big impact since joining on loan from sister club New York City FC.

The former England and Chelsea midfielder will miss this weekend’s trip to another of his old clubs, West Ham, in the Barclays Premier League on Saturday after suffering a thigh injury against Spurs.

Pellegrini said: “Frank is not ready for this week but maybe I think next week he will start working with the whole squad.

“It will be a short injury, less than we thought at the beginning.”

City face Newcastle in the Capital One Cup next Wednesday before hosting rivals Manchester United the following Sunday.

Lampard’s performances have led to speculation City could seek to extend his loan.

The 36-year-old is due to link up with New York early in the new year to prepare for the 2015 Major League Soccer season. There have been reports this could be facilitated by New York holding a pre-season camp in Manchester but Pellegrini would not be drawn on the matter.

He said: “One thing is not related to the other thing. Maybe New York City can work here in January but that is not depending on the future of Frank Lampard.

“We will see what is the future of Frank. For the moment he is here in Manchester City.”

City’s trip to Upton Park gives them a chance to cut Chelsea’s five-point lead at the top of the Barclays Premier League and apply pressure before Jose Mourinho’s men face Manchester United on Sunday.

City beat West Ham four times last season, scoring 14 goals, but Pellegrini insists that counts for little and has noted the fourth-placed Hammers’ good start this term.

He said: “West Ham are in a good moment, playing good, attractive football.

“They are scoring a lot of goals, they had an important win against Liverpool at home and they have won their last two games.

“I am sure we are going to have a very difficult rival, exactly as we have every game in the Premier League.”

Pellegrini is certainly pleased to get back to Premier League business after the frustration and controversy of Tuesday’s Champions League draw at CSKA Moscow. City conceded a disputed late penalty as the Russian side hit back from 2-0 down to snatch a 2-2 draw, leaving Pellegrini’s men with a battle to qualify from their group.

There were also further issues surrounding attendance as it appeared around 300 CSKA fans were admitted to a game that was officially played behind closed doors. It is thought they obtained sponsors’ tickets.

Pellegrini said: “I don’t want to link both things – the result and what happened with the fans. I think the only punishment was (for) our fans because they couldn’t go.

“For me, it is more important to talk about football, not to talk about rules or punishment, it is not my duty.

“Of course it was a frustration, we lost two important points.

“But in the Champions League the most important thing is to qualify for the next stage, so you can make a mistake.

“Where we cannot lose points is in the Premier League. Now all of us are thinking about West Ham.”