Anthony Riddle had heard enough.

While crafting a speech for an upcoming event, Riddle, a Marine sergeant who served three tours in Iraq and a 13-year combat veteran who now works for the government and lives in Jackson, listened to countless hours of college football talk on several networks.

There was an endless discussion about the youth and inexperience of Michigan’s football team and how that might sidetrack the team this season.

“All they had been talking about is the team is too young and too inexperienced,” Riddle, a lifelong Michigan fan, said in an interview this week with The Detroit News. “That’s bullcrap.”

He was so incensed, he diverted his attention from the speech and began typing a letter to Michigan coach Jim Harbaugh.

“We were all heading into WAR and were not even old enough to have a beer,” Riddle wrote. “I served in three tours to Iraq before I was 22 years old. How is that for being young?”

After consulting with some fellow veterans who told him he had nothing to lose sending the letter, he found an email address for Harbaugh.

“My whole thing is, who cares about the age and inexperience when we’re asking young men and women every single day to do this?” Riddle said of military service. “I’m sure (Harbaugh is) tired of hearing that. I’m sure that irked some of the players. You don’t get asked to play for Michigan and not be talented.”

Just more than a day later, Harbaugh replied and told Riddle he planned to share his letter with the team and asked him to come to Ann Arbor at some point to share his experiences. Riddle initially was certain someone was playing a joke on him.

“‘You said it better than I could say it,’” Riddle said of Harbaugh’s email response.

After Michigan’s season-opening victory over Florida, Harbaugh produced the letter and shared it with media members.

“I think his message was — it’s irrelevant what the age is,” Harbaugh said.

“His Marines and what they did and what they sacrificed and what they were able to do, age is irrelevant. So it’s a group of guys in a unit or on a team that come together and do their job. So Anthony Riddle of Jackson, Michigan, thank you. It was really on point, a lot of really good messages in it.”

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Defensive lineman Chase Winovich said the letter gave the players an extra burst.

“It was just inspiring,” he said. “If nothing else, it gave you that one percent faster in the back of our minds that there’s a lot more people giving a lot more sacrifices for this great country we have here.”

Riddle watched the game and not long after received a call from his sister. Her boyfriend had received a text alert, indicating Harbaugh had just read a letter from Anthony Riddle.

Suddenly, he was receiving text and Facebook messages.

“I shut all that down,” Riddle said. “It was overwhelming.”

Riddle enlisted in the Marines two weeks after high school graduation in 2000.

“I ended up being platoon sergeant for 52 Marines,” Riddle said. “(Embedded CNN reporter) Martin Savidge joked, ‘Man, you’re in charge, and you’re not even old enough to drink.’ So what? I know what I’m doing, we all trained hard.”

That’s what he drew upon when he wrote the letter to Harbaugh.

“I was at a young age I didn’t really know who I was at the time, and yet I’m being told, ‘You’re going to Iraq to invade,’” Riddle said.

Among his experiences during three tours was having the footage of the toppling of Saddam Hussein’s statue shot from his vehicle.

“It was humbling,” he said. “As we went into Baghdad, it was almost as though we were in a parade. People were running and cheering and giving us roses.”

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It’s clear Riddle would never compare the life-and-death aspects of war to playing football, but there is a shared necessity for teamwork.

“I was trying to make the point, I was within in a team, you’re within in a team and I rely on those men on the left and right of me as well,” Riddle said. “If I’m going to go out and train and work hard for every mission, that’s exactly what you’re doing in the offseason. You’ll make mistakes and you’re learning from those mistakes.

“It irked me when I kept hearing this stuff about the youth. That age thing is completely irrelevant. We were told straight from boot camp, the first thing you hear from drill sergeant, ‘Here’s what you should expect from us, but here’s what we expect from you. At all times give 100 percent, you’re never going to quit, and you’ll wear the uniform with pride and respect because of all the people who wore that uniform before you. When you put the uniform on, you’re no longer representing yourself, you’re representing a team.’ It relates.”

Riddle grew up a Michigan fan in a household of Michigan State fans.

“There is one picture of me wearing a State sweatshirt,” Riddle said laughing, “but I swear I was held down.”

At some point this season, Riddle will make his visit to a game in Ann Arbor as Harbaugh’s guest. He is thrilled for that opportunity, but now he relishes whatever impact he made on Harbaugh and the Wolverines.

“He got a hold of me Monday,” Riddle said of Harbaugh. “He said, ‘I read your letter to the team. Obviously, they responded well.’”

Twitter: @chengelis