Instead, she went to a corner and imagined herself on the apparatus, delivering one solid routine after another.
Then she went out and turned that imagination into reality.
Postell scored a 9.925 on the balance beam, capping a rally that gave the Utes a 196.175-196.1 win over No. 12 Arizona State on Friday, Utah's closest victory of the season.
"I like to go off on my own," Postell said of her isolation before performing. "If I see something bad, sometimes that affects me."
And there was plenty of bad to see moments earlier in the meet, when Utah nearly gave the win to the Sun Devils with its worst performance on the floor this year, a 48.5.
Kristina Baskett (9.45) and Postell (9.2) fell, with Baskett landing her first pass short and Postell putting her hands down during her last pass on floor, a triple twist.
Gritt Hofmann stepped out of bounds, a tenth deduction, and scored 9.725. Meanwhile, the Sun Devils posted a 49.0 on the balance beam.
The combined performances put Utah down 147.275-147.025 going into the final rotation.
"We didn't know what the score was," Utah coach Greg Marsden said. "All we knew is we completely decimated the floor."
Utah, coming off a 49.45 on the beam last week, put together another solid performance, scoring a 49.225.
Even with the high marks Utah needed some help from the Sun Devils to get the win, and the home team gave the Utes the break they needed when two competitors fell on the floor.
Their mistakes made it possible for a Utah win, as long as Postell delivered. The sophomore did, working through one of her quickest routines of the year.
"We were so disappointed about floor, I was just pissed off," Postell said. "I tried not to pause at all. I do better if I just get up there and stick it."
She was set up for a big score by junior Nicolle Ford, who scored a 9.875.
"We didn't look at the scores, but we figured we were down, we blew it on floor," Ford said. "At that point, we felt like we had nothing to lose."
Floor was the only spot Utah had any trouble, as the Utes scored 49.3 on the vault and 49.225 on the bars.
"I thought we did a nice job on three events, but I have no explanation for floor," Marsden said. "My impression was we were trying too hard. Ashley tried too hard at the end and buried herself, Gritt twisted too early and Kristina didn't stand up on her full-in. Those are all mental mistakes we can't afford to make."
Arizona State and Utah used to be the rivalry in college gymnastics, with the teams finishing 1-and-2 at the NCAA Championships in the 1980s.
But since then, the Sun Devils have struggled to stay even in the Utes' category, with the Sun Devils failing to reach the Super Six since a fourth-place finish in 1999.
The current Utes are unfamiliar with that history, but they didn't want to see their domination end. Utah has won the past four competitions with the Sun Devils.
"We always want to win and we knew what we were capable of," Ford said. "We heard about the rivalry, but more than anything we wanted to go out and do our thing."