Rookie receiver Darren Waller was tough to miss on the practice field Saturday afternoon.

The 6-foot-6 pass catcher from Georgia Tech literally stood head and shoulders above his counterparts.

"You have to look up really high when you talk to him," Head Coach John Harbaugh joked after rookie minicamp practice.

The sixth-round pick is a developmental prospect with plenty of raw talent.

At 6-foot-6 and 240 pounds, Waller has imposing size to create mismatches against players in the secondary. By comparison, he's four inches taller and 30 pounds heavier than cornerback Jimmy Smith, the biggest player in the Ravens defensive backfield. 

The physical tools are evident immediately, and the Ravens were also impressed with what they saw out of Waller on the field in his first weekend of action.

"The thing about Darren, and you see it, we saw it on tape, we saw it in the workout, but now to see it here on our field is the confirmation [of] how well he moves for a big man," Harbaugh said.

Waller has game-breaking speed, as he ran the 40-yard dash in 4.46 seconds at the NFL Combine. His speed is different compared to smaller, shifty receivers, as Waller's strength is his ability to pick up big chunks of ground with his long strides. 

"Now, he doesn't move like a 5-foot-9 receiver. He's long, he's fast, he gets in and out of breaks exceptionally well," Harbaugh said.

Regardless of how Waller covers ground, he has the kind of speed that defenses have to gameplan to stop. And his size makes him an ideal target inside the red zone. 

"He has [a big] catch radius, he can snatch the ball," Harbaugh said.

Waller's contributions were limited in college playing in Georgia Tech's run-heavy offense. He caught just 26 passes for 442 yards and six touchdowns. But other receivers have come out of Georgia Tech's offense to make the transition to the NFL. Denver's Demaryius Thomas had just 46 catches in his final year at Georgia Tech.

Waller is jumping into a tight competition at receiver, but the early indication is that he has all the potential to develop into a target for quarterback Joe Flacco. 

"We'll see where it goes from here, but so far so good," Harbaugh said.