Every NFL rookie gets their wake-up call, and for DJ Harris, it came on the final play of Chicago Bears rookie minicamp. The tryout cornerback found himself matched up against Scotty Miller—an eight-year veteran who knows a thing or two about winning, thanks to a Super Bowl ring earned catching passes from Tom Brady in Tampa Bay.

Miller ran a crisp go route, and Harris grabbed hold, fighting to stay in stride. Quarterback Maverick McIvor, a tryout player himself with stops at Texas Tech, Abilene Christian, and Western Kentucky, launched a pass down the right sideline inside the Walter Payton Center. Harris was all over Miller—if officials had been on the field, a yellow flag would have flown. But the crafty veteran hauled it in anyway, drawing cheers from the offensive side of the ball.

That's no knock on Harris. The Youngstown State product, who started his college career at Division II Tiffin, gave full effort. He'll get more chances Saturday. But Miller, a Barrington native, knows the league's tricks. He's a local product who could add valuable depth to the Bears' 90-man roster at wide receiver.

This two-day minicamp is a crash course for Chicago's seven-man draft class and other newcomers—on the field, in the weight room, and in the team's culture. Starting Monday, these rookies will mix with veterans during Phase 2 of the voluntary offseason program.

"It's more about just introducing them to our way of life," said head coach Ben Johnson before practice. "That's really the objective here. We had a good start last night. A lot of information was digested, and we'll see it come to life."

First-round pick Dillon Thieneman got his first taste of NFL action. The Bears ran circuit drills for 20 minutes, then Thieneman took reps at strong safety during 7-on-7 drills. No highlight-reel pass breakups today—the ball never came his way. But he'll be tasked with learning both safety positions, and on special teams, he lined up as the personal protector during some simulations.

For these rookies, every rep is a lesson. And with a veteran like Miller showing the way, the Bears' newcomers are getting a real education in what it takes to compete at the highest level.