(Reuters) - Norwich City striker Teemu Pukki has quickly adapted to the challenges of the Premier League and West Ham United must exercise caution when they host the promoted side, manager Manuel Pellegrini said on Thursday.
Pukki, who has scored in all three Premier League games, leads the goal scoring charts with five goals -- level with Manchester City's Raheem Sterling -- and has also provided an assist.
The Finnish striker, who was last season's top scorer in the Championship with 29 goals, could become only the third player to score in his first four games in the Premier League after Mick Quinn (Coventry City) and Diego Costa (Chelsea).
"When you have a change in competition, there are always some players who feel the difference. I think Pukki is demonstrating that the Premier League is not difficult for him," Pellegrini told reporters ahead of Saturday's clash.
"He's scoring goals and we will need to be careful of him. I expect a similar game to the one we played against Watford.
"Norwich play this system and they played exactly the same way against Chelsea and Liverpool. They are a very good team and we will need to play a very good game to get the three points."
After an opening day home defeat by champions Manchester City, West Ham have picked up four points in two away games and Pellegrini is looking for his first league win at home after winning 2-0 away at Newport in the League Cup on Tuesday.
"We had to play three games away in a row," the Chilean said. "We won two of them and got one draw, which gives us more confidence in what we're doing.
"Now we want to win our first home game."
West Ham striker Sebastien Haller, who cost the club 45 million pounds in the close season, got off the mark last weekend with two goals in a 3-1 win at Watford and Pellegrini now expects him to kick on.
"I think Haller will improve a lot because it takes time to learn the Premier League," Pellegrini added. "But scoring two goals in a game, especially after coming back from a small injury, will help him a lot."
The 65-year-old also said he would take a call on Michail Antonio, who suffered a suspected hamstring injury in the League Cup win, on Friday after he has an MRI scan while striker Javier Hernandez has recovered from his knee injury.