Baltimore Ravens head coach John Harbaugh has disclosed that his side are preparing for all types of formations ahead of the 2015 season.
The 52-year-old complained following his side's divisional round loss to the New England Patriots that some of the tactics used by Bill Belichick's men were "deceptive".
As a result, Harbaugh has admitted that he is preparing his team for everything they could possibly face for the new campaign.
"We are working on formations – legal formations, illegal formations, unexpected formations," Harbaugh told USA Today.
"The first time we ran it, you heard [Terrell] Suggs out there saying, 'That's not legal, that's not legal.'
"We will not assume that the referees are going to understand or always get it right when a formation goes out on the field, so we're working on everything."
The Ravens open their 2015 season against the Denver Broncos on September 13.