Hummel announced on Monday he is leaving that career behind to open some massage therapy centers in the Salt Lake City area.
Hummel has been with the program for 13 years, with his main responsibility being the uneven bars.
"It's a very emotional time for him and for us," Utah coach Greg Marsden said. "But it's an opportunity that he can't pass up and we're excited for him."
Marsden said he would start the search soon for an assistant.
"He has been with us 13 years, and we're going to look everywhere to replace him," Marsden said.
Hummel was named the NCAA regional assistant coach of the year in 1997 and '98 and is known for his creative bars sets.
"I was approached a year ago with an offer and I thought about it for a long time before making the decision to leave coaching," Hummel said. "I felt like I had to take this opportunity now because it might not come up again. This is one of the hardest decisions I've ever had to make and I feel like I'm leaving my family."