Thirteen weeks into the NFL season, we're well accustomed to the new universe of good Geno Smith, explosive Justin Fields and hapless Russell Wilson. Those are the breakout and declining performances that make headlines, but there are plenty more to uncover in the vast NFL universe.
Let's talk about the somewhat-under-the-radar breakouts and slumps, using some advanced metrics -- often with data from NFL Next Gen Stats -- as our guide. By their very nature, the breakouts will be relatively lower-profile names and the decliners will be higher profile. Let's take a look with five who have struggled:
Jump to a section:
Players who have declined
Dalvin Cook, RB, Minnesota Vikings
On the surface, Cook's numbers look fine -- 927 rushing yards, another 157 receiving and eight combined touchdowns. His 4.7 yards per carry is the same as a year ago. But there are sneaky signs of a decline here for the 27-year-old.