The moment happened so fast, so unexpectedly that Nic Shimonek didn’t get time to think.

He saw Patrick Mahomes II go down on the second play of Texas Tech’s second drive of the third quarter Thursday night. The Red Raiders, uncharacteristically sluggish on offense, lost their star quarterback in a flash, and Shimonek -- with one collegiate completion to his credit in three seasons before he threw for 150 yards in garbage time last month against Stephen F. Austin -- misfired on his first throw before settling in like an old pro.

"One of our sayings here," Shimonek said, "is to stay ready, so you don’t have to get ready."

In 15 minutes, 2 seconds, he tossed four touchdowns and threw for the bulk of his 271 yards on 15 of 21 passing as Tech rolled past the Jayhawks, 55-19.

Mahomes, among the top three nationally in raw QBR, passing yards, touchdowns and completion percentage, remains "day to day," coach Kliff Kingsbury said. He has an injury in the area of his right shoulder as the Red Raiders prepare for a trip Saturday to Kansas State (7 p.m. ET, ESPNU).

If Tech turns this week to Shimonek, a transfer from Iowa and former walk-on, he expects -- in his debut start -- to draw on the successful experience from his first pressure situation as a college quarterback.

"Not being afraid of anything or anybody is kind of my deal," Shimonek said. "I feel I can throw with anybody in the country. I have that much confidence in my arm, simply from all the work that I’ve put in."

Shimonek relied on his training Thursday. He stood tall behind the line. The 6-foot-3 junior made smart reads, Kingsbury said, and showed a quick release.

"I don’t know the two quarterbacks at all like Kliff does," Kansas State coach Bill Snyder said, "but it didn’t look to me like there was any drop-off."

In a word, Kingsbury on Monday described Shimonek as a "gunslinger."

"Nic’s a free spirit," the coach said. "He’s kind of his own cat, dresses a certain way and wears his hair a certain way and has got his tattoos and everything."

When Shimonek landed in Lubbock in the summer of 2014, Texas Tech coaches knew little of him.

"But what jumped out to me was his work ethic," Kingsbury said. "From day one, he worked as hard as anyone on our team. That impressed his teammates and impressed his coaches. He just got better and better and learned the offense and made himself into the player he is."

You’ll find him typically in sweat pants and a hoodie, Shimonek said, both of the cutoff variety. His closet includes some unusual stuff.

"I’ve got some pretty wild shoes," he said.

As for the ink that covers three-quarters of his left arm, Shimonek and his older brother, Jake, got nearly identical tattoos to commemorate their brotherhood after Nic’s first semester at Iowa in January 2014. Since, they have added elements -- both with sentimental significance and because Shimonek said he "thought it looked good."

Courtesy of Nic Shimonek

"Just being who I am," Shimonek said. "I’m not a big fan of caring what other people have to say about me. If you’ve got something good to say about me, good. I appreciate it. If you’ve got something bad to say, I appreciate that, too.

"It doesn’t really matter to me. That kind of goes with my personality in general. I’m always relaxed."

The mindset serves him well in football. Shimonek threw for more than 8,211 yards and 97 touchdowns at Mildred High School in Corsicana Texas, committing early to Iowa in the Class of 2013.

"The ball explodes out of his hand," Mildred coach Billy Dan Chambliess said.

He redshirted in 2013 and recognized that the Hawkeyes, offensively, did not match his most refined skills. Shimonek returned to Texas in the summer of 2014, with help from Iowa offensive coordinator Greg Davis in the search for a new school.

Ultimately, Shimonek forged an unlikely connection with Kent Hance, the now retired Texas Tech chancellor and former U.S. representative who knew the father of Shimonek’s girlfriend.

Hance passed word to Kingsbury of the quarterback’s willingness to walk on at Tech.

Shimonek sat for a second straight season in 2014 as Mahomes rotated Davis Webb after Baker Mayfield had transferred to Oklahoma and Michael Brewer left for Virginia Tech. When Webb left as a graduate transfer for Cal after Mahomes blossomed last year, Shimonek took over the No. 2 job.

Mahomes and Shimonek grew close after last season. In the spring, Shimonek said, they shared every football-related experience -- except the playing time.

No doubt, Kingsbury said, Shimonek’s rise at Tech began with "no red carpet."

"He earned every bit of getting here and getting a scholarship," the coach said.

Shimonek maintains his relationship with Hance. The former chancellor, in fact, called to wish him well after Shimonek’s standout relief showing against Kansas.

"He was pretty fired up about me taking advantage of that opportunity," Shimonek said.

So were the Red Raiders.

"We have a lot of faith in Nic, because he’s a hard worker," said receiver Jonathan Giles, who caught a 59-yard TD from Shimonek in the fourth quarter. "He’s a good kid on and off the field."

Shimonek said he’s preparing no differently this week than usual. It’s a credit to Kingsbury’s coaching, he said.

"He makes sure you’re ready at all times," Shimonek said, "so if something like this does happen with Pat -- you never want it to and can’t replace a guy like that with his intangibles -- the next guy has got to be ready to go. I really pride myself on that."