Las Vegas, Nevada - The head coach of the Las Vegas Raiders found himself in some hot water on Friday as an old email he sent was revealed to contain racially insensitive remarks.

Raiders coach Jon Gruden (58) spoke during a newly released interview with the Wall Street Journal to respond to the discovery of an old email that he sent which contained a racist trope in regard to NFLPA president Demaurice Smith.

The email, which was sent by Gruden in 2011 to the Washington Football Team, physically describes Smith as having "lips the size of Michelin tires."

African-Americans, like Smith, are often ridiculed for having naturally thicker lips than other racial groups, so Gruden's remark was easily seen as racially insensitive and inappropriate.

In the interview, Gruden apologized for the past remarks, but claimed that he couldn't fully recall writing the email.

When asked to comment by ESPN, Gruden said, "I never had a racial thought when I used it. ... I certainly never meant for it to sound that bad."

He explained the term "rubber lips" referred to people he thought were lying, though there doesn't seem to be any historical precedent for the term being used that way.

But speaking of tires, in 1997 the Goodyear Tire & Rubber Company formally apologized to the National Association for the Advancement of Colored People (NAACP) for a television commercial that they ran comparing a black man's lips to tires.

The misstep occurred ten years ago while Gruden was an analyst for ESPN, long before the NFL decided to finally "Inspire Change."

Smith responded directly to the Journal's report, saying, "This is not the first racist comment that I've heard and it probably will not be the last."

On behalf of the NFL, spokesperson Brian McCarthy said, "The email from Jon Gruden denigrating DeMaurice Smith is appalling, abhorrent and wholly contrary to the NFL's values."

The league is reviewing the matter and could possibly hand down disciplinary action in the near future, according to multiple sources.