Loss of pass rusher Rivers highlights Patriots' only weakness

No NFL roster is perfect, but the Patriots have amassed one of the most enviable collections of talent in league history ahead of the 2017 season.

Finding a discernible weakness on New England's roster is difficult, especially after the reigning Super Bowl champions somehow managed to significantly improve by reinvigorating its backfield, trading for speedster Brandin Cooks and snatching star corner Stephon Gilmore away from the division rival Buffalo Bills in free agency.

The only things that appear to stand in the way of the Patriots and a second consecutive Lombardi Trophy are injury or bad luck. However, there could be another major issue New England must find a way around: their questionable pass-rushing corps.

Third-round defensive end Derek Rivers, New England's top draft pick this year due to the team being without its first two selections, was set to be a significant contributor to a defensive line that lacked dynamic talent on the outside.

However, Rivers is out for the 2017 season after tearing his ACL. Suddenly, the Patriots' could have an Achilles' heel to exploit.

New England's defensive end depth chart is topped by Trey Flowers, who had seven sacks last campaign and is set for a breakout year in 2017.

But beyond Flowers, the Patriots don't have a lot of proven depth, especially after reliable veteran Rob Ninkovich retired in July after 11 seasons, robbing head coach Bill Belichick of not only one of the quintessential Patriots, but a player who'd contributed 48 sacks over the past eight seasons.

While Ninkovich's loss was unexpected, the state of the Patriots' pass rush is a fate Belichick has chosen.

Top pass rusher Chandler Jones was traded to the Arizona Cardinals in March 2016, and super-athletic linebacker Jamie Collins was sent packing to the Cleveland Browns midway through last season.

Nevertheless, the Patriots, as they always seem to do, still rose to the top of the mountain despite losing their premier sack man and middle linebacker who racked up 5.5 quarterback takedowns in 2015.

So while questioning Belichick's moves admittedly almost always ends in his doubters looking foolish, the head coach can't be excited about the state of the defensive end position right now.

Kony Ealy, whom New England traded for this offseason, has talent, but the inconsistencies that convinced the Carolina Panthers to trade him despite a historic performance in Super Bowl 50 are still present.

Rookie Deatrich Wise Jr. could be another option opposite Flowers, but he's dealing with a concussion and doesn't have the speed to consistently win one-on-one matchups, especially early in his career.

After Ealy and Wise, the Patriots' depth is just career special teamers and undrafted rookies.

Again, Belichick is a defensive wizard, often pulling miraculous levels of production from unlikely sources, but even for him, turning this group into a productive unit seems a tall task.

The Patriots finished tied for 16th last year with 34 sacks, and that was with Ninkovich and departed free agents Jabaal Sheard and Chris Long combining for 13 sacks.

How New England replaces that production, especially after Rivers' injury, could be the dominant question of their season.

Rivers' loss is a blow, but has also shined a spotlight on the weakness and should motivate Belichick to get creative to find reinforcements, either via trade or on the open market, where useful veterans like Dwight Freeney and Paul Kruger are still available.

Regardless, New England rightfully remains far and away the favorite to win Super Bowl LII, but even a small crack has the potential to take down the biggest behemoths.