Brook will challenge the 26-year-old American in Atlantic City, Detroit, on May 18 after their initial fight in February was postponed after Alexander injured his bicep.
Although Brook heads into the fight with 29 wins from his 29 fights to date, Alexander believes his opponent has no chance of handing him only his second defeat in 26 bouts.
"I'm excited that the fight is back on, although the fight was never off as I just had an injury and had to postpone the fight," he told World Boxing News.
"I have looked at enough Brook fights to see what I need to see and I'm not missing anything as he is a basic fighter.
"I haven't seen one fight that I was impressed with because he hasn't fought anyone of a high calibre.
"I haven't heard anyone from the US going for Kell, but if they are, they are just people who don't like me and want to see me lose.
"How can you go for Kell when 95 per cent of people in boxing don't even know who he is."
Initial reports suggested Alexander postponed his fight against Brook as he was eyeing a mouth-watering encounter against Floyd Mayweather Jr, but the American insists he is focusing on his next bout before he thinks about the future.
Asked about the possibility of a unification fight with Mayweather Jr later this year, he replied: "I'm not going to speak too much about the Floyd fight, but I'll tell you this, big things are coming for me after I brutalise Kell in May."