Huma said Northwestern seemed to be intentionally misconstruing the facts, and said the school's "subliminal messages" included the suggestion that a "yes" vote could throw their amateur status into question.
"No one is taking about striking," he said. "They are trying to rattle players."
Northwestern did not release the document publicly, but The Associated Press obtained a copy and the school verified its authenticity. Alan K. Cubbage, the school's vice president for university relations, dismissed Huma's suggestion that the school was using scare tactics.
"I would say strongly that Northwestern has conducted an election campaign ... according to the procedures and the rules of the NLRB," he said.
When outgoing Northwestern quarterback Kain Colter announced in January that he would lead the drive to unionize, helped by CAPA and the United Steelworkers, he said nearly all of his fellow teammates were behind him.
Trevor Siemian, who is expected to replace Colter as the starting quarterback, has said he will vote against a union.
"I'll say there's a significant number of guys on the team who feel the same as me," Siemian said this month.
Safety Davion Fleming said his teammates have slowly begun to understand that the issues aren't clear cut.
"When the union talk initially started, it wasn't very clear what was going on," said Fleming, who doesn't support unionization but can't vote because his eligibility is exhausted. "I think they didn't understand the implications."
After weeks of both sides vying for votes, Fleming said he detects a common sentiment among players.
"They just want this to be over — and to focus on football," he said.
AP Sports Writer Jay Cohen contributed to this report.
- Former longtime Utah Jazz broadcaster Hot Rod...
- BYU offense offers sneak peek for fans in...
- A not-so-Sweet 16 for the Runnin' Utes as...
- BYU players work out at Pro Day in hopes of...
- Former Jazz big man Enes Kanter goes off,...
- Former Duke and Utah player Chris Burgess...
- Brad Rock: Utes shouldn't feel bad, in spite...
- Brad Rock: Utah's Dallin Bachynski delivers...
- A not-so-Sweet 16 for the Runnin' Utes... 88
- Dick Harmon: Taysom Hill is making a... 31
- Guest commentary: Utah Jazz face an... 31
- Can Utes turn Sweet 16 dance into date... 27
- Photo gallery and video replay: BYU... 23
- It's Coach K vs. Coach K as Utah... 22
- Home games on the Sabbath: RSL... 21
- Dick Harmon: Henderson joins other BYU... 20