Breaking down center rotation

FOXBOROUGH, Mass. -- The Patriots kept four of the five positions on the first-unit offensive line intact throughout the first half of Thursday's preseason opener.

Left tackle: Nate Solder

Left guard: Donald Thomas

Right guard: Dan Connolly

Right tackle: Marcus Cannon

The only changes in the first half came at center, where three players were rotated. That would seem to reflect the view of an open competition at the center spot.

Here was the rotation by series:

First drive: Dan Koppen (12 plays)

Second drive: Ryan Wendell (7 plays)

Third drive: Wendell (3 plays)

Fourth drive: Wendell (6 plays)

Fifth drive: Wendell (3 plays)

Sixth drive: Koppen (6 plays)

Seventh drive: Nick McDonald (5 plays)