Then there are the tattoos. On one arm he has a Tasmanian devil with the phrase, "I have the fire." His newest ink is a lion with the St. Louis arch stretching over it, a tribute to his home town. The words "Beast in the City" accompany it.
Before games you might spot him praying. During games, you are likely to find him powering through the paint – unless he is on the bench pestered by fouls.
"Kalen is an interesting player. It is really up to him how much of a difference he wants to make. When he is motivated, getting the ball, and playing hard he is almost impossible to stop on the high school level," said Eric Bossi, recruiting analyst.
"His size and strength are obvious, but he is also surprisingly quick and has a nice spin move and touch on a short jump hook," added Bossi.
Grimes agrees his mass is one of his best assets.
"I have good size and dominate in the post," said Grimes. "I want to work on my defense and extend my game and shooting range."
"As Kalen develops more moves and improves his footwork he will become even more of a beast in the post," said Bossi.
"Also, as soon as he learns to adjust his game to the way the referees are calling it, he'll eliminate some of the foul trouble he gets in and will be able to play more aggressively."
This summer Grimes will have opportunities to show off his game, as well as work on adjustments. In June he will attend NBA Players Association Camp in Richmond and the USA Junior Olympic Development Festival in Colorado Springs. In July Grimes will join some of the nation's best at the Nike All-America Camp in Indianapolis.
"Illinois is close to home. My family could drive in for a game and drive back the same day," said Grimes.
"I have grown up with the Big 10. Illinois is probably the best school in the conference and I feel like I could help make the program better. I had been pretty much planning to go there."
What complicated this plan was Bill Self's move to Kansas. Self apparently likes what he sees in Grimes. At Illinois Grimes was considered a priority target for Self and the coaching staff. According to Grimes, Self contacted him the day after he left Illinois with another official offer - to become a Jayhawk.
"Kansas is Kansas," said Grimes. "I really respect Coach Self. He is the main basis for me looking at KU."
Missouri has its appeal as well.
"Again, it is close to home. It is a great school with a great coach. I'd have the chance to play with my friend Jimmy McKinney too."
Grimes stated the addition of big man Linas Kleiza to the Tiger roster was not a factor.
Grimes tentatively plans to visit all three schools, but nothing has been set.
"I will sit down and talk with my family," Grimes said.
In the meantime, Grimes has plenty to keep him occupied. When he is not on the court, Grimes says he is spending time in the weight room.
"Other than that I just like to go out with my friends, go to movies and stuff," said Grimes.
Fave music video. Girls, Girls, Girls by Jay Z
Are you a slob or a neat freak? A neat freak, but only because my mom makes me.
What past accomplishment are you proudest of? My freshman year I went to the Nike Hoops Jamboree in St Louis and was named in the top five in camp. I was surprised and it really made me want to work as hard as I could to see what I could do.
How about regrets? Anything you would do differently? Maybe take school a little more seriously my freshman year. I mean, I was serious but I probably could have done more.
Last really good movie you saw. Matrix Reloaded.