Speaking on BBC Radio 5 Live Breakfast, he said: "As a striker, you’re always going to be judged on the number of goals so it’s fantastic for him. You’re always going to need a striker who should be getting you anywhere in the region of 20-25 goals.
"He’s got off to a decent start although I still think he struggles with the Premier League, maybe the demands of the game. It’s different to the Champions League, where it’s a little bit more tactical and you can play at a slightly slower pace.
"He seems to fit into the Champions League so that record is really good. When you’re playing a struggling team that doesn’t create as much for you, then you’re always going to struggle."
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