Floyd Mayweather is a notoriously big gambler.

The boxer has been known to make bets of over $1 million on various sporting events, even tweeting pictures of his winning tickets. Now, Mayweather may have made his biggest wager yet.

According to the twitter account for sportsbook.ag, an online betting Web site, Mayweather reportedly placed a $3 million wager on Michigan for this Saturday's game. The Wolverines are opening their season against Alabama.

Michigan is a +14 underdog in the matchup. While the boxer has reportedly taken the points, 69 percent of the bettors on sportsbook.ag have taken the defending national champions.

Mayweather made news during the NBA Playoffs when he reportedly won a $1.8 million bet. The report says he took the Clippers in their Game One contest against the Grizzlies in the first round. Los Angeles overcame a 24-point deficit in the fourth quarter to get the victory.

With the return of college football this weekend, there is expected to be a lot of money bet on the upcoming games. The first games are set to get underway on Thursday, with South Carolina and Vanderbilt starting things off at 7.pm. ET.

Gamblers are taking No. 9 South Carolina more than any other team. Eighty-nine percent of bettors have put their money on the Gamecocks at -6.5.

The alleged $3 million bet has not been confirmed by Mayweather.