Complex sentence: Thirteen awardees also won the Super Bowl in the same season, with Kurt Warner being the most recent to accomplish this feat when he was named the 1999 AP NFL MVP and won Super Bowl XXXIV with the St. Louis Rams.
Split into simpler sentences: Thirteen awardees also won the Super Bowl in the same season. However, it has not occurred since since 1999, when Kurt Warner won Super Bowl XXXIV with the St. Louis Rams.