What if Trent Green did not get injured in the preseason in 1999?

The NFL staff has identified plays or events that may have altered the course of history. Each Tuesday and Saturday throughout the offseason, we will be tackling a different scenario and speculate on how things might have gone differently.

Kurt Warner's MVP campaign in 1999, capped off with a victory in Super Bowl XXXIV, ranks as one of the great Cinderella stories in the history of sports. But Warner's achievements would not have been possible without the misfortune of a teammate.

The St. Louis Rams hadn't reached the playoffs since 1989, but head coach Dick Vermeil believed he had finally found a capable quarterback in Trent Green. The 29-year-old had enjoyed a breakout season with the Washington Redskins in 1998, throwing for 3,441 yards, 23 touchdowns, and 11 interceptions, before signing with the Rams as a free agent.

He entered the preseason as the undisputed starter, but tragedy struck in the third exhibition game against San Diego, as Green suffered a season-ending injury. The Rams were forced to turn to Warner, who had spent the previous season in NFL Europe, and was only four years removed from working at the Cedar Falls Hy-Vee grocery as a stocker.

Warner, of course, seized his opportunity in a way few could have imagined. He added a second MVP award in 2001, leading the Rams to Super Bowl XXXVI, and hold the distinction of being the most accurate quarterback in NFL history, with a career completion rate of 65.6 percent.

Green left for Kansas City, where he has enjoyed six solid seasons as the teams starting quarterback. But he has never scaled the same heights as Warner, likely leaving Green, and fans in St. Louis, to wonder: What if he had not suffered the injury in the preseason?

-- David Mosse