That's because he had been through a hip injury before in high school. He's not exactly sure what the injury even was.
"I really don't know. I honestly don't. I didn't listen to the doctor. I just know I did the same exact injury again and I was going to be out for a while," Lumpkin said. "That's the only honest thing I can tell you.
"I knew right away it wasn't good when I felt it pop. I knew what it was. I couldn't pick up my leg. I couldn't lift my leg for a week and a half. I lost all motion and power in it. It felt just like it did in high school. It was the same exact injury."
Lumpkin lost strength and weight - he dropped from 290 to 278 pounds. "It was horrible. I got smaller. I have to get back up to where I was at the beginning of the season," Lumpkin said.
Afraid to miss out
He worried he might not even get back and miss what has already been a remarkable season for the Wildcats.
"I waited all year to get here and then next thing you know, I was out. I didn't know when I was going to get back," he said. "If you asked me two weeks ago if I be practicing now, I would have said I don't know.
"I was used to getting up, rehabbing and leading a regular student's life. No offense to them, but I didn't like it. I was used to getting up in the morning, lifting and running around and hitting people. It freaked me out that I wasn't going to be able to play. There was so much hype and so many people telling me I was going to do well - and I was doing good - and then I got hurt and had to wait again."
Lumpkin admitted he would be "nervous" putting on the pads today. He caught himself hopping instead of stepping properly at practice Tuesday. But he knows he needs contact work to prove to the coaches, and himself, that he's ready to play again.
"I don't know when I will play. I just know I am practicing again and working to get back in it. When they want me to play, I will be there," Lumpkin said.
"I am still sore and will probably me sore for a while. These are muscles I have not used for a month. I have to get back used to running, hitting, grabbing pads, shaking, diving and all that. I will probably be 100 percent eventually, but I will be sore."
Lumpkin understands he can't mistake soreness for pain.
"If it is going to be sore, it will be sore. At times, it doesn't hurt. It just depends on whether I turn a certain way or whatever," he said.
What Lumpkin won't do is worry about getting hurt again. He knows if he does, he'll not be able to play the way he should.
"I don't let it get to me. If it gets to me, then I won't be playing 100 percent. I will be second guessing. What if I fall again? What if the guard goes around me again and falls? I just have to go play and not worry about it happening again," Lumpkin said.
"I want to play again this season. When? I don't know. I just know I am going to do everything I can to make it happen because not playing has about killed me."