Since the NFL-AFL merger in 1970, there have been 18 times when a team went into a playoff game with a chance to complete a three-game season sweep, according to STATS, Inc. Those teams are 11-7. Here are the previous matchups, with the team that won both regular-season games listed first, along with the postseason result:
1989 Houston Oilers vs. Pittsburgh Steelers Lost
1991 Kansas City Chiefs vs. Los Angeles Raiders Won
1992 Kansas City Chiefs vs. San Diego Chargers Lost
1993 Los Angeles Raiders vs. Denver Broncos Won
1994 Minnesota Vikings vs. Chicago Bears Lost
1994 Pittsburgh Steelers vs. Cleveland Browns Won
1997 New England Patriots vs. Miami Dolphins Won
1997 Green Bay Packers vs. Tampa Bay Buccaneers Won
1998 Dallas Cowboys vs. Arizona Cardinals Lost
1999 Tennessee Titans vs. Jacksonville Jaguars Won
2000 New York Giants vs. Philadelphia Eagles Won
2002 Pittsburgh Steelers vs. Cleveland Browns Won
2004 St. Louis Rams vs. Seattle Seahawks Won
2004 Green Bay Packers vs. Minnesota Vikings Lost
2007 Dallas Cowboys vs. New York Giants Lost