"It looks like it's broken again, the same finger," Mason told reporters after the loss. "It doesn't look good."
Mason underwent X-rays after the game and was seen in the locker room with his finger wrapped. He plans to have the finger examined Friday in Baltimore, according to the newspaper.
Mason has 34 receptions for 447 yards and three touchdowns this season, including four catches for 48 yards and a touchdown against the Falcons.
The Associated Press contributed to this report.