Austin will embark on his debut season in the NFL having been selected by the Rams as the eighth overall pick in this year's draft.
The 22-year-old is renowned for having impressive acceleration, and Mayock believes that such an attribute could see him become a huge success at the Rams.
"I watched all of his tape, I saw him in person at his pro day. He might be the most explosive player I've ever seen in my life, from a static start to full speed," Mayock told reporters.
"He's almost impossible to cover in short spaces. So the ways you can use this are basically only constrained by the imagination of your offensive coordinator."
The Rams will take on the Cleveland Browns in their opening pre-season match on Thursday, as they continue preparations for the start of the new NFL season that kicks off on September 8.