As he drove to the basket with seconds remaining in a tie game, he thought he was going to get his chance. And then he was knocked to the floor.
Officials awarded him two free throws, but he landed on the wrist that had been bothering him most of the season, and he lost feeling in it.
He couldn't take the free throws that would ultimately put his team ahead.
"I did want to take those free throws," Tiller said. "That's one of the things, when you're in practice, 'Yeah, I'm going to get a game winner one of these days.' Today was my day, and I didn't get to do it."
Coach Mike Anderson looked down his bench and pointed at freshman guard Kim English, a 65.2 percent free-throw shooter, 10 percent worse than Tiller, who ranked second on the team.
"I saw it in his eyes," coach Mike Anderson said of selecting English. "I felt it in my gut. Sometimes you just have to go with your gut feeling."
While Marquette fans booed and called Missouri cheaters for the substitution, English walked up to the free-throw line and coolly knocked down two free throws to give Missouri an 81-79 lead with 5 seconds remaining.
"I was actually telling [guard] Marcus [Denmon] to get ready because that's who I thought he was going to pick," English said. "Every player on that bench would have made those two free throws."
Once those shots went down, Missouri seemed charmed.
"I've been to Boise; this is my fourth time," Anderson said of first- and second-round appearances with Arkansas and UAB. "I guess I'm finally getting a chance to advance, so I guess the fourth time is the charm."