Horrell was outstanding in his first start against the Cheetahs in Bloemfontein and has rarely looked back.
"That was one of my goals at the start of the year," he admitted. "If I did get a chance, I really wanted to make sure I took it wholeheartedly."
People talk about the step up from ITM Cup to Super 15 as being this vast chasm, but playing at fullback offers you a few luxuries other positions might not enjoy. Horrell escaped the raw physicality that jolts the younger forwards back to earth. He found he had more trouble adjusting to the altitude in South Africa and the humidity in Durban and Brisbane than he did the step up in class.
The 23-year-old has made such an impression in the No 15 jersey it is easy to forget he was signed by Hawkes Bay from Canterbury as a first five-eighths.
"I don't really have a preference now. I've played a bit at second five-eighths as well. To be fair, I don't mind as long as I'm out there. I know everybody says that but I honestly don't really care."
His proficiency at fullback can be traced back to his high school days.
Playing in a 1st XV that included Colin Slade, Matt Todd, Owen Franks, Nasi Manu and Tim Bateman, you tended to play where there was room and that happened to be at the back, with Slade running the show at first-five.
Horrell made the decision to move north to the Bay when his opportunities were blocked at Canterbury.
"I couldn't even make the academy at Canterbury so it was a no-brainer really," he said.
Horrell can expect to be targeted tonight. If there's two things Bulls first five-eighths Morne Steyn can do, it's launch a pinpoint bomb and kick goals. His critics would probably say his 74 per cent success rate in 2012 is down slightly, but his 167 points are 15 more than the next best, Aaron Cruden.
He also needs one more conversion to have booted 200 conversions in Super rugby. Only Dan Carter has more. Likewise, his total of 206 penalties is second only to Carter.
"We have to make sure our discipline is right on the money," said Liam Messam. "Hopefully we won't give him a chance to kick three points."