Rookie first-round quarterback Lamar Jackson stepped onto the field with the veterans this week and elevated his game.
Asked for his take on how much progress Jackson made between rookie minicamp two weeks ago and the start of Organized Team Activities, Harbaugh said, "he's doing a much better job."
"He's a talented guy; he's practiced well every practice he's been out here," Harbaugh said.
The biggest learning curve for Jackson so far has been in calling plays. Louisville had a pro-style scheme built around Jackson's unique dual-threat talents, but the coaches called in the plays from the sideline to their respective position groups.
Thus, simply calling the plays in the huddle has been an adjustment for Jackson.
Offensive Coordinator Marty Mornhinweg and Quarterbacks Coach James Urban have worked and helped him. During Thursday's practice, Mornhinweg would lean in just outside the huddle and listen to Jackson making the calls.
"I would say he's made a big jump in calling the plays and annunciating the offense," Harbaugh said. "He's done well with that."
Harbaugh praised Jackson's arm talent and accuracy during rookie minicamp, and Jackson seemed to throw the ball even better in Thursday's practice.
He was particularly strong in red-zone drills, where he lofted a perfect back-shoulder throw to rookie receiver Jaleel Scott and zipped a few throws into tight windows. Jackson also had a nice throw to the sideline for Scott and continued to have a good connection with his rookie tight ends.
What drew the biggest reaction from his teammates, however, was when Jackson would take off running. Jackson's speed and elusiveness juked several defenders out, drawing cheers from even the defenders standing on the sideline.