Harbaugh was asked if the Ravens needed to upgrade the position after the retirement of Birk, a six-time Pro Bowl selection.
“We’re always going to try to be as good as we can be at every position, obviously," Harbaugh said. "Gino did a nice job last year. He played really well in the Bengals game, which we felt like that was a big test for him. We had an opportunity to see him against a really good defensive line, and he held up. He’s a little more physical and stout than he may look, and he’s got great feet.
"He’s a smart guy and it matters to him. He’s our center. He’s at the pole position right now. He’s got probably the edge there, but if we bring in somebody to compete with him, if it works out that way, that’d be great.”
Gradkowski spent his rookie season soaking up knowledge from Birk: learning how to snap the football precisely to quarterback Joe Flacco, how to diagnose defenses' blitz and stunt packages to make line calls, and acquiring the work habits of a professional offensive lineman.
As the lone center on the roster, Gradkowski is poised to replace Birk as the Ravens' new starting center. A Pittsburgh native, Gradkowski approaches football with a blue-collar style.
"I don't think I could ever replace a guy like Matt, especially off the field, with his leadership qualities in the locker room," Gradkowski said. "He's unlike any other person I've ever been around. I'm just excited for the opportunity. I know I'll have to earn this spot because nothing is ever just handed to you."
Birk strongly endorsed Gradkowski, who played in every game last season with his most extensive action coming in a regular-season finale loss to the Bengals, where he was in for 73 of 89 offensive snaps.
"Gino will be fine," Birk said during his retirement announcement in February. "The one thing about football is there's a lot of tangible things or requirements that you need, but I think the biggest thing about football is that it's a character game, because it's hard.
"It's different from other sports, and Gino's got that. He's a great guy. He's got a fantastic family, and Gino will do whatever it takes to be successful."