Lyerla told the Oregonian that he had been sick and missed practice between Tuesday and Thursday, and he was told to stay home Saturday and rest.
But when reporters asked Helfrich about Lyerla's absence from Autzen Stadium after the game, Helfrich had a one-word response: "Circumstances."
When reporters asked Helfrich to be more specific, the coach smiled and replied, "Circumstances is extremely specific. That's one word.''
Lyerla said he was not amused that his coach failed to mention he was simply ill.
"I'm really upset with the way Coach Helfrich said that after the game,'' Lyerla told the Oregonian on Sunday. "Really disappointed. I feel hurt about this. I watched a little bit of what he said, then started reading all of it, and ... it was unfair.''
Lyerla was held out of nine practices last summer for what the team called "personal issues," according to the Oregonian, and Lyerla said he thought Helfrich's response opened the door to speculation.
"I have no idea why he said that,'' Lyerla said. "It made me really upset. It's not my fault I got sick. I just felt he could have had my back a little bit more instead of throwing me under the bus.''
Helfrich told reporters on Sunday evening that he has used the same verbiage with multiple players this season and he didn't think "circumstances" carried any negative connotations.