Coach Kyle Shanahan knows his 49ers will have their hands full against Kyler Murray on Sunday at Levi's Stadium.
San Francisco faces its NFC West foe for the first time this season, and while the defense did square off against Murray in Week 15 last year, the elusive Arizona quarterback had just recovered from a torn ACL that he sustained the prior season and didn't quite look like himself.
Shanahan was asked before practice Wednesday how different the Cardinals QB looks through four games this season, compared to last season's matchup.
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"He just looks so much more comfortable," Shanahan told reporters. "I thought he looked really good last year when he came in, just watching their offense, seeing him in that new scheme for the first time. I think he got to sit back and watch other guys do it. And then him coming in, you could tell he really consciously tried to play within the confines of the offense, which was different to see, just how the scheme was before.
"And then always when he isn't playing in the confines of the offense, how he can be the scariest guy in the league. Kyler has always played at a pretty high level, when he is healthy, and he's doing that right now."
Murray has completed 75 of 108 passes (69 percent) for 777 yards and six touchdowns with one interception and also run 16 times for 164 yards. Murray -- with the addition of star rookie wide receiver Marvin Harrison Jr., plus a healthy James Conner and Trey McBride -- has a better supporting cast around him than he did last season.
San Francisco's defense historically has struggled against mobile quarterbacks. If Murray can escape the pressure up front, he will make the 49ers pay.