MANKATO -- It was 10 years ago today that Vikings right tackle Korey Stringer died of heat stroke following a training camp practice.

The Vikings have painted Stringer's number, 77, on the practice field closest to the stands in Mankato and have planned a moment of silence before today's opening practice of camp. Coach Leslie Frazier talked today about Stringer at a team meeting.

The Vikings also are doing everything in their power to make sure a tragedy like Stringer's death never happens again.

Eric Sugarman, the team's head athletic trainer, addressed players today for about 20 minutes on the issue of proper hydration and what happens if they get dehydrated. That is even more important this year because there are so many new players in camp -- rosters will start at 90 players -- and the Vikings were unable to communicate with players all offseason because of the lockout.

"I show them some studies on if you lose a certain percentage of your body weight then your performance goes down a certain percentage," Sugarman said. "I don't just make it up, it's from studies that have been done. ... Try to educate them on that. Then I go through basically the process of what we do here at Mankato and throughout the course of the season when we're not in Mankato to help these guys fight heat illness and fight dehydration."

After Sugarman spoke to the players, strength and conditioning coach Tom Kanavy addressed the subject of nutrition. Sugarman later spoke to the media about exactly what the Vikings do to not only encourage proper hydration but also how they deal with any potential heat issues that might occur.

This includes using urine testing, having water and Gatorade available just about everywhere a player can look and having some players ingest a pill that enables the Vikings to monitor their core body temperature with a personal digital assistant.

"I can't prevent someone from getting an ACL injury, I can prevent someone from getting heat illness most of the time and that's really important," Sugarman said. "That the first thing I told these guys in my talk today. The second part of that I tell them, 'It is impossible for me to do it without your help.'"

Sugarman said the topic of what happened to Stringer does come up. "You have to," use that as an example, Sugarman said. "It's not to demean or anything. It's a shame that it happened and you don't want for it to ever happen again. ... Coach talked to the team about Korey today."

Single-game tickets to go on sale

Vikings single-game tickets and multi-game packages will go on sale at 9 a.m. Wednesday in person at the team's ticket office at Mall of America Field at the Metrodome. Cash or credit cards will be accepted but no checks.

At 10 a.m. tickets will be available in person at all Midwest Ticketmaster locations, by phone through Ticketmaster at 1-800-745-3000, or via the internet at www.ticketmaster.com.

Single-game tprices range from $39 to $143. Single-game tickets will be available for all preseason and regular season games with the exception of the Green Bay (Oct. 23) game. Anyone buying a ticket to the Packers game also will have to buy one for the Sept. 1 preseason game against Houston. Two-game packages range from $78 - $286.

Williams joins 49ers

Safety Madieu Williams, who was released by the Vikings last week, has agreed to terms with the San Francisco 49ers according to Matt Maiocco of CSNBayArea.com.