… Despite losing 10-6 in a low-scoring preseason opener to the Denver Broncos, the San Francisco 49ers were fairly pleased with their play overall. The backups struggled offensively, but that is to be somewhat expected. With three more preseason games remaining, here’s a look at three keys to keep an eye on.

Continued Secondary Improvement
Going into the season, many had some worries about the secondary for the 49ers. After one game, it looks pretty good. Led by cornerback Perrish Cox, the team did a great job limiting Denver’s passing attack. Tramaine Brock had the task of trying to limit Demaryius Thomas, and he did a good job in the limited action both players saw. Eric Reid also looked impressive at safety, which is perhaps the best news for those worried that he would take some time to adjust to the NFL level.

Running Back Depth
Frank Gore is starting to get up there in age, so having depth at running back is essential for the 49ers this season. After the first preseason game, Anthony Dixon may not be the best running back, but he is a true football players. His numbers show just 27 yards for seven carries in the first game, but he had his best runs taken away due to penalties (don’t rely on these numbers come fantasy football draft day. As great as he looked, the 49ers also have LaMichael James and Kendall Hunter to turn to when things get tough - both of who will likely start head of Dixon. With Michael Crabtree out and the passing game hurting a bit, running back depth is essential.

Finding A Crabtree Replacement
In Week 1 of the preseason, the 49ers are nowhere closer to finding a true replacement for Michael Crabtree. Their star wide receiver, who is out indefinitely with a torn Achilles, was essential to Colin Kaepernick and the passing game. AJ Jenkins was the first player to get a shot at replacing Crabtree, but he looked terrible against Denver. Marlon Moore should get more reps throughout the rest of the preseason, and he might even be considered the favorite now to take Crabtree’s spot.