Kranjcar added: "We know England's strengths - their players all play in the Champions League and week in week out in the Premier League.
"We are surprised they have struggled, but they have it all in their hands. They possess the quality to qualify, but I don't think it is going to be that easy."
Meanwhile, coach Slaven Bilic insists Croatia cannot afford to play for a draw.
"A point at Wembley is always a good result but you can't play for a point," he told BBC Radio 5 Live.
"We'll do everything to represent our country in the best possible way."
The former West Ham defender promises his team will not be set up just to stifle England.
"We are coming to play a serious game and try to keep the English players far from our goal but that is easy to say," he said.
"Nobody is favourite when they play away against England so we would be happy for a point but you can't guarantee you'll keep a clean sheet.
"It is a big, big match. It is every player's dream to play at Wembley. We will play our normal game."
Bilic also reiterated his backing for under-fire England manager Steve McClaren.
McClaren's job was under serious threat before Israel's shock victory over Russia on Saturday and his long-term position remains in question.
Bilic said: "He has got what he wanted and he deserves it but Steve McClaren is extremely unlucky in every game he plays because he is missing three or four important players with injury.
"We're playing England and it depends who will be the better team on Wednesday and we hope it's us. It will be difficult for both teams."
