In six and a half games now, second-year inside linebacker Sean Lee has shown to be one of the best young defensive players in the NFL.
He now has 51 tackles and three interceptions before leaving Sunday night's game in the first half with a wrist injury.
It was that injury that showed just how good Lee has become, or at least how much the Cowboys will miss him if he's out for any extended amount of time.
Things weren't going great for the Cowboys defense, which entered Sunday's 34-7 loss to Philadelphia as the No. 1-ranked unit in the league against the run, before Lee was injured. But it got really bad after he left.
The Eagles and running back LeSean McCoy shredded the vaunted Cowboys rush defense for more than 200 yards on the ground and McCoy finished with 185 yards and two touchdowns.
A lot of that is because aging vets Keith Brooking and Bradie James were seeing more playing time in Lee's absence, and showing just why they don't play much anymore when the second-year Lee is healthy.
Brooking and James have been great assets to this team in their tenures, but it's clear they can longer cut it as starters in the league. They were both exposed in the running game and more notably in the passing game, where Lee has excelled this season.
Lee is set to have an MRI today to determine the severity of his wrist injury.