Source: Albert Haynesworth will play

Despite their contentious relationship, Washington Redskins coach Mike Shanahan has decided defensive tackle Albert Haynesworth will play in the season opener against the Dallas Cowboys on Sunday night, a team source said Saturday.

Haynesworth has been informed that he will play primarily on passing downs, rushing from an inside position. Haynesworth could start the game if the Cowboys open with a three-receiver set, the source said.

The Cowboys practiced anticipating Haynesworth would be on the field.

The Redskins normally dress five defensive linemen but plan to have six in uniform Sunday.

The number of snaps Haynesworth will play has not been determined. It will depend upon his performance and the type of game that evolves.

"It could be five plays or 35 plays," the source said.

Ed Werder is an NFL reporter for ESPN.