Jim McIngvale, the owner of the Houston-area Gallery Furniture chain who is known as Mattress Mack, is placing $4 million worth of bets Saturday on the 2021 Kentucky Derby.

McIngvale has gained notoriety in recent years for large wagers on sporting events to offset promotions at his furniture stores, with those offers usually related to Houston teams.

He told Byron King of Bloodhorse he was going to bet on the morning-line favorite, Essential Quality, because his latest promotion called for people who purchased a mattress valued at $3,000 or more to receive it for free if the Kentucky Derby favorite won the first leg of the Triple Crown.

"It's another day at the furniture store for me because I have done this so many times," Mattress Mack said Wednesday. "Obviously, I have a vested interest in the favorite winning because if the favorite wins, the customers get free mattresses, and they give us positive PR and word of mouth for the next 10 years. So I have a very vested interest in the favorite winning. But let's put it this way—a two-minute sweat is a lot less stressful than a three- or four-hour baseball sweat."

He's waited until race day to place his bets because if he did so Friday when wagering opened at Churchill Downs on Kentucky Oaks day it would have completely pushed the betting lines out of whack.

"When to bet it is the key question," McIngvale said. "Obviously, if I bet $2 million on Friday, the odds will go down to 1-9. I'm trying to provide value on these other horses for bettors to get odds more normalized on Essential Quality."

The Derby favorite is undefeated in five career starts with four straight victories in Graded Stakes races, the Claiborne Breeders' Futurity, Breeders' Cup Juvenile, Southwest Stakes and Blue Grass Stakes.

Post time in the Run for the Roses is set for 6:57 p.m. ET on NBC.