When Julian Edelman went down clutching his knee during the Patriots' opening series against the Lions on Friday, the worst was feared. It turns out, the Patriots are fearing the worst, too.

According to ESPN's Adam Schefter, the Patriots suspect that Edelman tore his ACL. He'll have an MRI on Saturday.

This is an awful development, both for Edelman and the Patriots. 

He's their most important playmaker outside of Rob Gronkowski. Last year, he caught 98 passes for 1,106 yards and three touchdowns. In the Super Bowl, he made the biggest play of the game, coming down with the circus catch of the century.

Before going down with the injury Friday, Edelman was on fire against the Lions, hauling in three receptions for 52 yards.

If Edelman, 31, really did tear his ACL, there's no guarantee he'll be able to regain all of his explosiveness when he's coming off major knee surgery. The injury happened so late in the preseason, so there's a chance he'll still be rehabbing when next season begins.

In June, Edelman signed an extension with the Patriots, but that extension doesn't mean he's guaranteed to hang around in New England through 2019. According to Spotrac, the Patriots can cut Edelman next year and save more than $3 million in cap space. Considering the Patriots' lack of loyalty to anyone not named Tom Brady, that wouldn't come as a total surprise given Edelman's age.

This season, the Patriots should be able to compensate. After all, they still have Gronkowski, Brandin Cooks, Danny Amendola, Dwayne Allen, Chris Hogan, and a great combination of running backs coming out of the backfield. Brady is still arguably the best quarterback in the game. The Patriots will probably be fine. They're still the best team in their division.

But losing Edelman will undeniably hurt the Patriots' aspiration to win another Super Bowl.