The undefeated San Francisco 49ers finished their 35-16 win over the Arizona Cardinals in Week 4 with just one injury. 49ers head coach Kyle Shanahan revealed the lone casualty was offensive lineman Jon Feliciano. The latter “will enter concussion protocol this week,” per ESPN's Nick Wagoner.

49ers running back Christian McCaffrey carried San Francisco on his back against the Cardinals in Week 4. McCaffrey scored four touchdowns in the victory. He racked up 106 yards and three touchdowns on the ground. He also added 71 yards and one touchdown in the air for good measure.

Christian McCaffrey now has a permanent place in the 49ers' franchise record book. He has scored a touchdown in 13 consecutive games for San Francisco. He edged Hall of Fame wideout Jerry Rice in that statistical category on Sunday. McCaffrey also became the first player since 2014 to rack up at least 100 yards from scrimmage and a touchdown in the first four games.

Kyle Shanahan's decision to make Brock Purdy his starting quarterback has also paid huge dividends for the 49ers. Purdy has thrown for 1,109 passing yards and five touchdowns through Week 4.

Brock Purdy has been one of the most accurate quarterbacks in the league so far. He has yet to throw an interception this season. However, the stat that leaps off the page is his gaudy 72.3 percent completion rate. Purdy completed an insane 20 of his 21 passes against the Cardinals on Sunday. His impressive performance prompted Kyle Shanahan to sing his praises.

Of course, the 49ers' offensive line deserves plenty of credit for protecting Brock Purdy. However, they will miss a key contributor in Jon Feliciano against the Dallas Cowboys in Week 5. It's a showdown between the 49ers' second-ranked offense against the Cowboys' second-ranked defense. This game promises to be one of the best in Week 5, for sure.