The forward has scored three goals so far this season, and has netted four times in Swansea's three previous games at Stoke since their promotion to the Premier League.
Rangel told Wales Online: "They have [Victor] Moses, [Marko] Arnautovic, and [Oussama] Assaidi, good players than can create problems, but Crouch is the one, he's the threat.
"Any ball in the box, even if it's not a good cross, then it becomes a good cross because he is so high. And he can score goals. He's got quality and I think he's a great striker in the Premier League and he's shown that for so many years.
"He may seem clumsy but he's not and you can't under-estimate him. If they play a long ball to him, then either with the chest or the foot, he will pull it down and make his team play. You could see that when they got three points against Newcastle, with simple crosses and simple headers. That's what they do. It's a tough one for us, but we have been working hard all week and we'll try to stop him."
Swansea are currently seventh in the table, while Stoke are three points behind in 15th.