And the result of a city council vote Tuesday to declare the field a heritage site could send Toronto Pan Am Games organizers scrambling to come up with a Plan B.
"We were absolutely blindsided by this," said Ian Troop, president and CEO of TO2015. "We're hopeful that cooler heads and reason will prevail at the council meeting."
The university was scheduled to break ground July 1 on its $9.5 million Pan Am Games project for field hockey and para soccer that would see the grass replaced with a hybrid artificial turf.
One the one side are those who are argue about the lack of decent fields in Ontario, and the need to upgrade a patch of grass that has long been deemed unusable for good chunks of the year.
On the other: those who worry about environment sustainability, heritage and history issues, and access to the field.
Even Margaret Atwood has waded into the fray.
The Canadian literary icon, and U of T alumnus, posted on Twitter last week: "So, @UofTNews: as a soon-to-be dead alum w. $ to leave, am I annoyed by the anti-green plan? Y!"
Suzanne Akbari, a professor of English and medieval studies, said 31 of 34 members of the University College Council voted in opposition to the Pan Am plans when they first learned of them last fall.
"This is not about being obstructionist," Akbari said. "This is not about trying to tear things down, interrupt planning. It's trying to make sure we have a situation that we're all happy with, where Pan Am is being accommodated, the athletes are having a great experience, and the students that use that space, not just today's students but future generations of students, get to have it as a legacy for them as well."
Akbari, an administrator for the "Keep the University of Toronto Back Campus Green" facebook and Twitter accounts, said two large U of T student groups — the Arts and Science Student Union, and Graduate Student Union — have been vocal in their opposition.
Coun. Adam Vaughan will present a petition with about 5,200 names opposing the plan to city council on Tuesday.
Scott Sandison, an Olympian in field hockey, is circulating his own petition in support of a facility he said will help meet a "massive need in this city."
The Toronto native, who competed at the 2008 Beijing Olympics plus two Pan Am Games and has 178 caps for Canada, said he was forced to move to Vancouver to pursue playing on the national team because of the lack of decent facilities in Ontario.
"There's no support," Sandison said. "I remember when I was a kid starting to play in Toronto, and we'd go to tournaments and there'd be 15 or 20 fields just packed playing over an entire weekend. Now, every year there's less kids, there's less teams playing because we don't have a facility.
"There's an interest out there, it's just trying to tap into that so we can get the sport going again because it's really struggling."
A new field hockey facility in Brampton is the only one of its kind in Ontario.
Sandison works for Right to Play — a global organization with a mission of creating a healthy and safe world through sport and play.
In a letter to Vaughan, Sandison wrote: "We currently work with over 1,000,000 children on a weekly basis teaching children life saving messages through sport and play. These positive community values extend across language, boundaries and culture.
"This, in my opinion, is one of the best things about sport, and I really hope that our community will realize the opportunity that this artificial surface will provide."
Bruce Kidd, a U of T professor and Olympian in track and field, said there have been plans to upgrade the back campus field for 20 years.
Ontario University Athletics has banned what Kidd called a "mud bath" for intercollegiate competition because it's too dangerous. To keep the grass in proper playing condition would mean keeping people off it most of the time, he said. One major rainfall coupled with a rugby or soccer game could make it unplayable for weeks.
"The overuse and the weather has made it harder and harder to use for its original intention which was a playing field," Kidd said.
Kidd said the facility would be an elite field hockey development hub for eastern Canada, but would also solve a problem for university intramurals.
"There are huge waiting lists for intramural teams in the field sports," Kidd said. "And as a general rule, participation increases three times with turf. That's the experience of the university on the new Varsity Field, that's the experience of the City of Toronto and its fields, that's the experience of the school board.
"The city itself is turfing grass fields, the school board is turfing grass fields, private schools like Upper Canada College and St. Mikes are turfing those fields, and to the best of my knowledge there's never been any controversy about their fields."
Akbari said if the aim is a high performance sport facility, a better solution would be to build on the existing facility in Brampton. She planned to propose that to Bal Gosal, Canada's Minister of State for Sport, in a preliminary phone meeting Monday.
Kidd argued there are too few fields for a city the size of Toronto.
"Sadly Toronto is way behind the rest of the country. It's an unhealthy city. A generation ago it was one of the best," he said. "But we've fallen so far behind other Canadian cities."
Akbari argued students won't be given access to the fields after the Games, and cites documentation from FIH — the world governing body for field hockey — that says pitches cannot be kept at international standards for field hockey if they're used for other sports as well.
According to Sandison, those international standards only apply to stadiums hosting major events such as a World Cup or Olympics.