"You are the leader now, like it or not," Bisciotti said during his speech at the team's ring ceremony last Friday, according to the team's website.
The Ravens' roster has undergone a heavy turnover after their Super Bowl championship, including the retirement of defensive leader Ray Lewis, the loss of safety Ed Reed to the Houston Texans and the trade of Anquan Boldin to the San Francisco 49ers.
Flacco signed a six-year, $120 million contract with the Ravens this offseason after being named the Super Bowl MVP in a postseason during which he threw 11 touchdown passes and no interceptions.
Bisciotti praised Flacco for staying true to his personality during his five seasons with the team.
"Not many guys do what you did in five years. Not many did it your way," Bisciotti said, according to the team's website. "Not many like the way you do it. But I said at the end-of-the-year press conference after last year's [AFC Championship Game] defeat, that I think the fans of Baltimore will be rewarded by your low-key presence, and it will stand the test of time. Indeed it did, and we all hope it continues to do that."
Flacco said "it was pretty cool" to hear Bisciotti's words and "I'm honored that he would bring me up," according to the team's website.