After earlier saying Cardinals quarterback Logan Thomas would play at least the first half Sunday at San Francisco, coach Bruce Arians said there are "no plans on how long" the rookie will play, reports ESPN.com. Thomas will be making his first start after Ryan Lindley predictably flopped Week 16 against Seattle.

Thomas has appeared in two games, completing 1 of 9 passes. That completion was an 81-yard touchdown to running back Andre Ellington.

Quarterback Drew Stanton (knee) isn't expected to be ready until the playoffs, so Lindley is the only option behind Thomas. Lindley has zero touchdowns and eight interceptions in 225 career pass attempts. Arizona has not scored a touchdown in its past two games.

A 6-6, 250-pounder out of Virginia Tech, Thomas had a "shaky" start to Wednesday's practice before finishing "pretty strong," according to Arians.

Arizona is a 6-point underdog Sunday. The line opened at 4.5 before bettors pounced on the 49ers.

Despite their offensive struggles, the Cardinals can win the NFC West with a victory and a Seattle loss to the Rams.