JACKSONVILLE, Fla. -- LeShun Daniels grew up with the late Minnesota Vikings right tackle Korey Stringer. They attended Ohio State together. They were virtually the same age -- 27 years old -- with their birthdays just two weeks apart. Though Stringer was a Vikings starter and Daniels a backup who was on and off the roster, they spent parts of four seasons together on the Vikings.

"He's my best friend. He's my brother," Daniels said as tears welled up over Stringer's death early Wednesday morning.

Daniels, a member of the Jacksonville Jaguars, stayed in contact with Stringer through the opening of training camp.

"He was in great shape," Daniels said. "He came into camp around 350. He was working out, lifting, running. So I thought he would have been fine up there this year."

Stringer left Daniels a message on his cellular phone Monday, but trying to coordinate conversations between friends during the double-sessions of training camp is too tough. At 11 p.m. on Tuesday night, Daniels received a call from Vikings offensive line coach Mike Tice. The news had him shaking.

	“	Losing a good friend is pretty tough. ”
		— LeShun Daniels, friend of Korey Stringer

"He told me Korey was hospitalized and that his body had shut down because of the heat," Stringer said. "I guess the heat index around Minnesota was around (110 degrees) yesterday."

At 3 a.m, Tice called another time. Tice told Daniels that his best friend had died. A lot of things flashed through Daniels' mind. He thought of Stringer's family. Their children were in the same pre-school. Daniels said he knew that Stringer had taken care of all of his insurance for his family.

"Losing a good friend is pretty tough," Daniels said.

Daniels is 6-foot-1 and 304 pounds, not as big as Stringer. Being a big guy, he knows the difficulty of trying to stay hydrated during those hot summer days. In fact, Daniels has an edge. His wife runs a food service program, so he believes he is more educated than a lot of players.

"I know a lot of guys take nutritional supplements to try to maintain their weight or take different vitamins to try to stay on top of their game," Daniels said. "I read in the paper a couple of days ago that a couple of Florida guys passed away from just working out. You are starting to see it a lot now. There is a lot of pressure being put on athletes to be in tip-top shape just so you are able to compete.

"A lot of the big guys have to come into camp at a certain weight, so they are cutting weight -- not eating, drinking and living on water."

Daniels said that players need to know the limits of their body, to know when to stop and rest a while.

"You got to know your limits," Daniels said. "That's another part of competing. You got to know how far you can go and when to stop."

John Clayton is a senior NFL writer for ESPN.com.