Shore up the offensive line
The offensive line has some of the more elite players in the NFL on the inside, as guys like center Rodney Hudson, and guards Gabe Jackson and Kelechi Osemele are Pro Bowl talents. The issue with the offensive line in 2018 was the fact they had two rookies at the tackle spots, as they were forced to start Kolton Miller and Brandon Parker.
While Miller was a first rounder, and was likely slated to start on the right side, the fact that Donald Penn was injured for most of the season forced him to start on the left. That led to Derek Carr getting sacked a career-high 51 times, which is something that cannot continue if this team is going to get to a Super Bowl.
Carr showed when he has time that he can be one of the best quarterbacks in the league, but he was under duress nearly every time he dropped back. Miller should be a solid player moving forward, but Parker needs time to develop, and there just was not enough depth on this roster up front to help him.