That was a decidedly difficult reaction from Hatsu Hioki. Truth be told, the Japanese fighter was the promotion's first choice as a challenger, but he asked for one more fight before competing for the belt.
So despite the fact that the call came as a bit of a surprise to the 23-year-old Koch, he wasn't about to turn down the opportunity.
"It's awesome," he said at a Wednesday press conference in Calgary, the site of July 21's UFC 149. "This is 23 years in the making. I've been doing this since I was a little kid. Just to be here and to get a chance, especially against a dominant champion who's an awesome champion, it's an awesome test. I'm just really excited."
If Koch wins, he will become the second youngest champion in UFC history, just behind current light-heavyweight kingpin Jon Jones, who at the time of his title win was about one month younger than Koch will be when he faces Aldo at July 21's UFC 149.
If there is one asterisk to that "youngest champion" clause, it's Aldo, who was just 23 years, 2 months, 10 days old when he beat Mike Brown to capture the belt back in 2009, about six months younger than Jones was when he won the belt. Of course, at the time, Zuffa only promoted a featherweight division in UFC sister company WEC. He was later promoted to UFC champ when the brands merged, and he's never relinquished his grip on the belt, mostly by demolishing whoever has been placed before him.
For his part, Aldo wasn't surprised about Koch getting the call.
"I think it was actually a well-deserved nomination," Aldo said through his interpreter. "Erik has a good rank and I wasn't actually so surprised even though there were some other interesting names. I'm up for the challenge. I think it's fair he's going up for the title because he's been going through a long list of fights previously with the WEC."
Koch (13-1) has won four straight since his only career loss, which consequently came against Aldo's last challenger, Chad Mendes. Since then, he's rattled off victories against Jonathan Brookins, Raphael Assuncao, Francisco Rivera and Bendy Casimir, with three of the four coming via stoppage.
Still, it will be a long leap from that to facing the likes of Aldo (21-1), who hasn't lost a fight since 2005 in fashioning a 14-fight win streak.
It may be a challenge, but it's one he's embracing.
"There's a lot more exposure and a lot of things I've got to do, but to me, a fight's a fight," Koch said. "I've never really gotten super nervous before a fight. It's something I just love to do. So I don't think there will be really any jitters. To be on top of my game, I know I have to be mentally sound. I have to be in the right place, and I'm always good at getting there. So, I don't think I'll have a problem with it."