"We knew it would be controversial," Mayock said, according to Vincent Bonsignore of the Las Vegas Review-Journal. "We completely understand that."
The Raiders entered the opening round with a need at tackle after trading starter Trent Brown to the New England Patriots.
With the 17th overall pick, Las Vegas chose Leatherwood - who some considered a second-round talent entering the draft - over higher-rated tackle prospects such as Oklahoma State's Teven Jenkins and Virginia Tech's Christian Darrisaw.
Mayock said the Alabama product became a favorite of the Raiders' staff leading up to the draft.
"(Offensive line coach Tom Cable) has been all over him for months now," Mayock said. "(Head coach Jon Gruden) loved this guy. Our scouts loved this guy. And what I like is, when the second floor in our building, which is all the coaches, and the third floor, which is all the scouts, when we're united on a conversation like Leatherwood, that makes me feel really good about the pick."
Leatherwood gives the Raiders positional versatility with the ability to work at guard or tackle. The 22-year-old isn't concerned with his critics or questions about where he'll line up in his rookie campaign.
"As far as a position, we haven't talked about it yet," Leatherwood said. "And to be honest, it doesn't matter. I'm just happy and excited to be a Raider. I'm going to be the best at whatever position I play."