Willis' chances of playing appear better

SANTA CLARA, Calif. -- Patrick Willis said last week he was hopeful to play after suffering a groin injury in Week 3, but caution won out.

This week, it sounds as if Willis truly has a chance to play.

“Last week, I really tried to push it to go and it just wasn’t all the way there,” Willis said Thursday. “What I didn’t want to do was lie to myself and teammates and not give all of myself. Me and the training staff felt it was the right approach. (Wednesday), it was better. I’m still feeling it a little bit but it’s certainly a lot better than it was.”

Willis practiced on a limited basis both days this week. Barring a setback, I think Willis has a chance to play, but the final decision will likely be made on the field Sunday prior to the game.

Defensive tackle Ray McDonald missed his second straight day of practice with a biceps injury. However, both McDonald and 49ers’ coach Jim Harbaugh said he is expected to play through the injury because there is little risk of further damaging the bicep.

Meanwhile, defensive lineman Justin Smith practiced on a limited basis Thursday after sitting out Wednesday with a shoulder injury. I’d expect him to play against Arizona barring a big setback.