Just don't expect results any time soon.
After the vote, the ballot boxes will be sealed for weeks or months - perhaps even years - as an appeal by the Evanston-based university runs its course.
The full National Labor Relations Board agreed Thursday to hear the school's appeal of a regional director's March ruling that the players are employees and as such can unionize, triggering a rule that the ballots be impounded.
Last month's decision by the Chicago-area head of the NLRB, Peter Ohr, sent shockwaves through the world of college sports, prompting sharp criticism from Northwestern and college athletic departments nationwide.
There have been no raucous rallies or demonstrations on the 19,000-student campus just north of Chicago, only official notices about the vote posted near the Wildcats' locker room. There has been plenty of lobbying in the form of private meetings, calls and emails, and everyone from coach Pat Fitzgerald to NCAA President Mark Emmert has called for a "no" vote.
The 76 scholarship football players eligible to cast ballots know the spotlight is on them, said Ramogi Huma, president of the College Athletes Players Association, which would represent the players at the bargaining table if the pro-union side prevails.
Players were seen heading into a campus building Friday where ballots were being cast throughout the morning.
Some of the pressure they feel stems from dire Northwestern claims about the consequences of unionization, he said.
"They're looking at anything and everything to invoke fear in the players," said Huma, a former UCLA linebacker and a longtime critic of the NCAA. "We feel like some of the tactics are scare tactics."
Northwestern, which is required by law to let the vote proceed, denies applying undue pressure on players to vote "no." It did send a 21-page question-and-answer document to the players outlining the problems with forming a union. In it, Northwestern said it hoped unionization would not lead to player strikes in the event of a dispute - but that if it did, replacement players could be brought in to cross picket lines.
"The tension created in such a situation would be unprecedented and not in anyone's best interest," it said.
The school also said divisions could emerge between scholarship players eligible for union membership and walk-ons, coaches and staff.
"There is no question but that the presence of a union would add tension in terms of creating an 'us' versus 'them' feeling between the players it would represent and those it would not," it said.
Northwestern did not release the document publicly, but The Associated Press obtained a copy and Paul Kennedy, a spokesman for the university's athletic department, 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.
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 can't vote because his eligibility is exhausted. "I think they didn't understand the implications."
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."
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.
Fleming also said he doesn't support unionization, though he said the drive has prompted a much-needed debate about conditions for players. After weeks of both sides vying for votes, he 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.