Thursday's first full-squad workout in training camp will begin the daily reports about how Joe Flacco and the rest of the offense are taking to Gary Kubiak's new plays and schemes. But not all of the Ravens' visible changes will be on offense. I interviewed coach John Harbaugh last month for an article that will run in The Baltimore Sun in the next couple days, and he made it clear that there was significant time spent this offseason on addressing some of the team's defensive woes from last year.