A day after the Ravens were visited by boxing legend Muhammad Ali at their practice facility in Owings Mills, they hosted another one of the greatest athletes in modern history at Monday night’s season opener at M&T Bank Stadium. Olympic swimmer Michael Phelps stood on the sideline and watched pregame warm-ups. And as they headed into the tunnel to make final preparations, he slapped hands with running back Ray Rice.

Ali also attended the game and watched from a private suite. He apparently left before halftime.

Phelps, the 18-time Olympic gold medalist, who showed his Ravens pride by wearing a white and purple plaid button-up shirt with dark, slim-fitting jeans, was there with his mother, Debbie, and other friends and family.

Phelps served as an honorary captain before the game, and took part in the pre-game coin toss. He ran out of the tunnel with a purple Ravens jersey. He wore No. 12 that had Phelps on the back.

About a dozen Orioles players are in attendance, including pitchers Jim Johnson and Tommy Hunter, infielders Mark Reynolds and J.J. Hardy, outfielder Adam Jones and utility man Ryan Flaherty.

Former Orioles Cal Ripken and Brady Anderson were also at the game.