Oakland Raiders fans have every right to be excited this offseason. Second-year quarterback Derek Carr is looking good and will hopefully take the next step in his development this year. Fourth overall pick Amari Cooper was wowing people at OTAs. Many expect a breakout season from linebacker Khalil Mack. Yes, there is a newfound sense of optimism in Oakland at the moment. But let's not get too carried away. This team still has holes and areas of weakness.

But which need looms largest? It's a question that was posed to ESPN Raiders reporter Bill Williamson.

"It's pass-rusher," he answered. "The Raiders had just 22 sacks last season, which was tied for the second-fewest in the NFL. Oakland's defensive ends had seven sacks in 2014, which was the fewest in the NFL. Despite having nearly $70 million in salary-cap room, the Raiders did not add an established pass-rusher in free agency. In the second round of the draft, the Raiders did take Florida State defensive end Mario Edwards. He had just eight career sacks in college and is considered more of a run-stopper than a pass-rusher. The Raiders are hoping outside linebacker Khalil Mack, who had four sacks as a rookie last year, will develop into a premier pass-rusher. He has to. No other sure things were brought to Oakland this offseason."

For a point of comparison, Kansas City Chiefs linebacker Justin Houston posted 22 sacks by himself last year. Clearly, the Raiders need to get after opposing quarterbacks more frequently in 2015.

Mack will have a larger role in the pass-rush this year after excelling in coverage during his sensational rookie season. Outside of that, it's doubtful defensive end Justin Tuck has much left in the tank at 32 and coming off a 5.0 sack season. The Raiders are slowly but surely adding quality pieces to its roster. Perhaps another pass-rushing option is still one year away.