Marshall, who recently signed a £17.8m, three-year Bears extension, said that Mike Shanahan was a very detailed coach, but Trestman is a man that he admires.
"I've played for some great coaches," Marshall told the club's official website. "Mike Shanahan was a great coach, X's and O's, one of the best in the business.
"What I'm about to say about coach Trestman has nothing to do with football: best in the business. So thankful that you're here, coach. Coach is amazing. He's a man that I look up to. He's a man that I would like to be one day."