Sarah Thomas is making history again.

Thomas became the first full-time female referee in NFL history back in 2015, and on Sunday, she'll become the first woman to officiate an NFL playoff game when the New England Patriots face off against the Los Angeles Chargers.

The trailblazer spoke to CBS News' Jeff Glor back in 2015 about learning she'd become an NFL referee.

"You never expect it but when it comes, you definitely answer the call but I was just about speechless," Thomas said.

Sarah Thomas is the first woman hired by the NFL as a full-time referee. CBS News

She also explained to him why she tucks her hair under her hat while she's on the field.

"To truly blend in," Thomas said. "If I have a ponytail, you know, then I separate myself immediately. So tucking my hair, I blend in and I'm just another official."

Long before she suited up in stripes, Thomas was a college basketball standout and recalled her own brushes with the refs.

"Maybe at times when they made a controversial call that I didn't think was right, I voiced my opinion but I think they would get just as aggravated with me at times, too," Thomas said. "When I started in football officiating, I had no idea the pride and the amount of time that they put into trying to get the game right."

Sunday will mark the third playoff showdown between Patriots quarterback Tom Brady and his Chargers' counterpart Philip Rivers. The two players will also be making their own history on Sunday as the oldest starting quarterbacks in a playoff game ever, with a combined 78 years between them.