PITTSBURGH (AP) — Pittsburgh Steelers quarterback Ben Roethlisberger is expected to miss Sunday's NFL game against the Baltimore Ravens because of a concussion.

Persons familiar with Roethlisberger's status spoke to The Associated Press on condition of anonymity on Saturday because the team has not made an announcement.

The development would force Dennis Dixon — who has thrown only one pass in two NFL seasons — to make his first NFL start in a game the defending champion Steelers might need to win to make the playoffs.

Roethlisberger practiced all week despite sustaining his fourth concussion since 2006 during a 27-24 overtime loss against Kansas City last Sunday. On Thursday, during his only interview of the week, he said he had been cleared to play, joking he passed "thousands of tests."

Roethlisberger, however, experienced headaches resulting from the concussion — his head struck the knee of Chiefs linebacker Derrick Johnson — and he began debating the wisdom of playing after consulting with the team's medical staff.