When Johnny Unitas made a guest appearance on "NFL 2Night" two years ago, it was the biggest thrill I've had in my six years at ESPN.

I remember the production meeting. It was as if royalty had entered the building. Other than calling him "Sir," I didn't know what else to say. And when he spoke in the meeting, everybody kept their mouths shut and listened.

I was more than honored to sit next to him on the "NFL 2Night" set. In fact, I didn't feel worthy. I felt like it should have been the host, Mark Malone, and Unitas talking football. But at the same time, it was a great feeling, like, "Man, this is Johnny Unitas. I can't believe it."

Although I played in the NFL and work as an analyst, I still asked him for his autograph. And why not? As a quarterback, Unitas was the toughest man who ever played -- and ever will play -- the position. He is still one of the game's measuring sticks. When people talk about toughness and the greatest quarterbacks of all time, his name is mentioned in the first breath.

Although I didn't get to see him play during his heyday, I had long admired Unitas, and I liked him even more after I met him. After the first meeting, he and I became friendly. We sat next to each other once on an airplane. We also spent about 45 minutes talking in the Cincinnati airport. We talked about quarterbacks, about golf and about travel.

I could sit and listen to Johnny Unitas talk about football for 24 hours straight. He had such a sharp mind. He used to love telling stories, and I was just mesmerized.

I used to ask him about calling his own plays. He told me when he got in the huddle, Raymond Berry would say to him, "I can get this guy." So Johnny would tell Raymond, "Well, give me this post-corner, and I'll get it there on time." That's how he would tell Berry to run a route -- as if they were two kids drawing up plays and playing in the street. He didn't know if the play would work, but they trusted each other.

The last time I saw him, other than his arthritic hands and fingers, he seemed to be in such good health. It's a sad day for the NFL. Fortunately, we have great highlights of Unitas that we will be able to see forever. I know the handful of chances I had to visit with him were unforgettable.

Former NFL quarterback Sean Salisbury is an analyst on "NFL 2Night," broadcasts on "The Dan Patrick Show" on ESPN Radio and contributes each week to ESPN.com during the NFL season.