It's raining on Vancouver's parade.

A day before the big game, city residents unfurled their umbrellas Saturday morning to watch the Grey Cup parade in downtown Vancouver.

But the 50,000 fans attending Sunday's game may need umbrellas, too, after some water was spotted leaking through BC Place Stadium's new $500 million fixed-cloth retractable roof.

"The day before the big game and it's raining INSIDE the new BC Place. Just a few drips, but surely not what PAVCO wants," CTV British Columbia's Shannon Paterson tweeted on Saturday evening, referring to the Crown Corporation responsible for the site.

Work crews began repairs immediately in an effort to keep the facility dry before fans fill the stadium for the game between the B.C. Lions and the Winnipeg Blue Bombers on Sunday.

Earlier Saturday, "Glee" star and Victoria native Cory Monteith served as the Grand Marshal for the Grey Cup parade, leading 100 "Raise the Roof" dancers, numerous floats and 14 marching bands through the streets.

"It is an honour to serve as Grand Marshal," Monteith told organizers of this 99th Grey Cup. "I love any excuse to come home and this is a thrilling one."

The Grey Cup festivities will continue at halftime in the game that begins at 3:30 p.m. Vancouver time (6:30 p.m. Eastern). With the Canadian rock band Nickelback playing a concert, the usual 14-minute halftime show will be extended to 28 minutes.

But even with 50,000 people pouring into the streets after the game, Vancouver police are not concerned about a repetition of the violence that followed June's Stanley Cup riot.

In fact, the riot squad won't even be on duty and most of the police officers will be directing traffic, according to Const. Lindsey Houghton.

"It's a very different event than we saw in the Stanley Cup finals," he said.

"The Stanley Cup finals was seven games of building up and this is one game on Sunday, at the end of November, not in the middle of June, that will be three hours of hopefully Travis Lulay throwing a lot of touchdown passes to Geroy Simon."

But police will be watching for public drunkenness, the same as at other large events, and will be handing out $200 tickets to those who openly consume alcohol.

There were no police on hand at Friday's CFL alumni luncheon -- but that may change in the future.

According to witnesses, two ex-players in their 70s got into a physical altercation after watching a video that showed highlights from the 1963 Grey Cup game.

The clip showed ex-Hamilton Ticats defensive lineman Angelo Mosca drilling B.C. Lions running back Willie Fleming in what many saw as a late hit. Fleming left the game, which Hamilton won.

Supposedly to show there were no hard feelings today, former Lions quarterback Joe Kapp, 73, offered Mosca, now 74, a bouquet of flowers. That's when the punches were thrown.

According to witnesses, Mosca used his walking cane to ward off Kapp's punches.

With files from The Canadian Press