Brock Purdy had a Christmas Day to forget in every sense as the San Francisco 49ers suffered a blowout defeat to the Baltimore Ravens.

Purdy was intercepted four times in a performance that may well have ended his hopes of being named the NFL MVP as the 49ers came out a comfortable second best in a primetime battle of number one seeds.

And it was a display he was not allowed to finish after Purdy suffered a recurrence of the stinger he sustained in the 49ers' win over the Arizona Cardinals last week, leaving the game after a sack by Jadeveon Clowney in the fourth quarter.

Purdy was cleared to return but, with the 49ers facing an uphill climb down by two touchdowns late in the fourth and with their offensive line very much a patchwork unit following injuries to Trent Williams and Jaylon Moore, head coach Kyle Shanahan made the decision to have backup Sam Darnold finish the game.

Darnold went eight for 14 for 81 yards, a touchdown and an interception that sealed the game for the Ravens.

His performance is unlikely to change the identity of the starting quarterback for the 49ers' game with the Washington Commanders on New Year's Eve.

However, with the 49ers needing to win out to clinch the one seed after a game in which Purdy crumbled, the scrutiny on him entering that game will be increased for reasons entirely unrelated to the MVP award.

NFL could make new rule after big play in Ravens-49ers

A change could be coming after this incident.