Tony Gonzalez has said that he believes Matt Ryan will become one of the NFL's elite quarterbacks in the future.
The recently-retired Atlanta Falcons tight end described his former teammate as an "excellent quarterback" earlier this week, but added that he is not currently among the best in the league.
The 37-year-old told CBS Sports Radio: "I've said it throughout the season. It's not a matter of 'if' but 'when' Ryan becomes elite. Work ethic really separates him.
"There's no stopping him when [wide receiver] Roddy [White] gets healthy and Julio Jones gets healthy and the offensive line becomes solidified. He's an inch away from being elite.
"Second class of QBs, Ryan, [Philip] Rivers, [Cam] Newton, [Ben] Roethlisberger, Russell Wilson. For anybody to say anything different about Ryan, it's somewhat embarrassing on their part."
Gonzalez, who has not ruled out returning during the 2014 NFL season, also claimed that Ryan is the best quarterback that he has ever played with.