ALLEN PARK, Mich. -- Detroit Lions coach Jim Schwartz is good at keeping secrets.
This time, though, he insists there isn't a secret to keep.
"You know that I don't see any reason to announce things like that early, because it makes things easier for the other team, but there hasn't been a decision made," Schwartz said. "There are still some factors that we have to deal with before we make that call."
The first question is Stafford's health. The rookie separated his left, non-throwing shoulder late in a dramatic 38-37 win over Cleveland, and was ineffective four days later in a Thanksgiving Day loss to Green Bay. He aggravated the injury in a Dec. 6 loss to Cincinnati and has sat out the last two games.
"We haven't ruled Matthew out yet, but there's still a significant amount of pain," Schwartz said. "If that remains, he won't play this weekend."
Stafford's injury opened up a spot for Culpepper, but the Lions lost 48-3 in Baltimore on Dec. 13 and trailed Arizona 17-0 at the half on Sunday. Counting a 26-0 loss in Green Bay on Oct. 18, when Stafford sat out with a knee injury, the Lions had been outscored 91-3 in 10 quarters with Culpepper as the starter.
Schwartz said he won't decide until later in the week if Cherilus and Ramirez will regain their starting jobs.
"We hadn't scored in about a month, and my blood pressure was too high at halftime," Schwartz said. "We couldn't just stand pat. Was it extreme? Yes. Was it warranted? Yes. We've shown all year that we aren't going to shy away from making changes, whether that's to the 53-man roster, the 45 players we dress on Sunday or the 22 starters."
Culpepper and Stanton didn't play particularly well against the Cardinals -- both had an interception and fewer than 100 yards passing -- but Stanton had one key advantage. The Lions scored 24 points in the second half, tying the game twice before losing on a late touchdown.
"Drew did some good things and he did some not-so-good things, but he moved the team and he put points on the board," Schwartz said. "One of our touchdowns came on the interception return, but that's still 17 offensive points, and that's a good half in the NFL."
That doesn't mean Stanton has taken the No. 2 spot away from Culpepper, though.
"In this league, the quarterback is always going to get too much credit and too much blame for what the entire team does," Schwartz said. "Drew is going to get the benefit of the doubt from people because we scored in the second half, and Daunte is going to get the brunt of the blame for the first half, but it isn't all them in either case."
Lions players had Monday off before a rare Tuesday practice. The schedule change is designed to allow them to have Christmas off before the trip to San Francisco. ... CB Phillip Buchanon (shoulder) is expected to miss much of the week's practice. His status is unsure for the 49ers game. ... Schwartz said CB Brian Witherspoon, signed last week, could return kicks against San Francisco.