When the NFL announced the shift to a virtual offseason in March, Baltimore Ravens defensive coordinator Don “Wink” Martindale immediately flashed back to his days of teaching economics and business to teenagers.

"As an old high school teacher, I taught some boring subjects,” Martindale said. "So, you have to be creative.”

Over the past couple of months, Martindale’s goal was to build a championship culture. To do that, he needed to entice his players to sign on to videoconferencing.

How could Martindale get his players as excited to pick up iPads as football pads? Coach John Harbaugh brought in former players Ray Lewis, Ed Reed and Steve Smith Sr. to talk to the team, and Martindale decided to take it up a notch. He came up with his “Chasing Greatness” series, which featured speakers who were champions from different sports and eras.

The list of people who addressed the Ravens’ defensive players included: Tony Siragusa, a defensive tackle from Baltimore’s 2000 Super Bowl team; Larry Holmes, a heavyweight boxing champion in the late 1970s and early 1980s; Ryan Howard, the slugging first baseman for the 2008 World Series champion Philadelphia Phillies; Eric Weddle, one of the leaders from the Ravens’ 2018 AFC North champion team; DeMarcus Ware, the pass-rushing end for the 2015 Super Bowl champion Denver Broncos; Julius Erving, the above-the-rim star for the 1983 NBA champion Philadelphia 76ers; John Calipari, the coach of the 2012 NCAA Division I champion Kentucky Wildcats; and Brandon Scott, Baltimore’s presumptive mayor-elect.

"I wanted to make it must-see Zoom meetings,” Martindale said. "You do get Zoom fatigue. I wanted to make it where they couldn’t wait to come to the defensive meetings. We wanted to make it an event. We wanted to build a champion mindset. That was the most important goal we had this offseason. I think we hit a home run with the speakers we had.”

Here are some of the messages delivered by the speakers:

Holmes: He was the sparring partner for Muhammad Ali before eventually beating him in the ring, which should resonate with the practice squad and undrafted players. "He didn’t care if he got paid or not,” Martindale said. "He was learning from the greatness. He took every day that he went to work as a lesson.”

Howard: His emphasis was being an underdog. Howard wasn’t drafted out of high school and went to Missouri State to play in college. “Ignore the depth chart,” Howard told the players. "Just become undeniable with what you want to do.”

Weddle: He provided perspective of his experience in Baltimore to his time with the Chargers and the Rams. “If a coach tells you had a good practice, that’s not good enough,” Weddle said to the players. "Don’t walk into that building unless you want to be great.”

Scott: A 36-year-old Baltimore native who won the Democratic nomination for mayor, Scott spoke to the players about the future of the city and outlines the ways they can help. "You could see the greatness in him,” Martindale said. "He’s an inspiration.”

It became even more important this year for Martindale to emphasize the Ravens' culture, which has produced some of the best defenses over the past two decades. Unlike a Ravens offense that returns all but one starter, Martindale faces more of a transition on defense.

Baltimore is returning 68.5% of its defensive snaps, which ranks 21st in the league. The Ravens revamped their front seven, adding a couple of veterans along the line (end Calais Campbell and tackle Derek Wolfe) and drafting two linebackers in the first three rounds (Patrick Queen in the middle and Malik Harrison on the weak side).

Baltimore has tried to gauge how much of the system the players have absorbed remotely. There has been a virtual walk-through as well as fun quizzes with "Jeopardy!" and "Family Feud."

The Ravens are among the teams scheduled to report to training camp on July 28.

"When we get to training camp, we’ll find out who is All-Zoom team and who can play football,” Martindale said.