Minnesota Vikings star wide receiver Justin Jefferson went down hard at training camp and had to leave the practice field on Friday. Jefferson suffered a left shoulder injury, but luckily the injury isn't believed to be serious, per ESPN's Adam Schefter. It's a sprained AC joint, with more tests to come to confirm.

Here's video of the play:

Let's hope this initial prognosis is correct and the injury isn't serious. A long-term injury to Jefferson would be a devastating blow to Minnesota's passing attack. The 22-year-old is looking to build on an outstanding rookie campaign, so a long absence would be brutal.

Jefferson had a historic rookie season with the Vikings after going 22nd overall out of LSU in the 2020 NFL Draft, catching 88 passes for 1,400 yards and seven touchdowns. The youngster broke several Randy Moss records during his prolific rookie year.

It has been an eventful training camp so far for Minnesota. In addition to Jefferson going down, there have been COVID-19 issues and some wild comments bandied about by Kirk Cousins. Vikings head coach Mike Zimmer has been noticeably frustrated with the COVID problems.

Furthermore, Minnesota's other first-round pick, Jeff Gladney, was recently released after he was indicted on domestic violence charges.

The Vikings are hoping to improve upon a mediocre 7-9 record. A healthy Jefferson would really help that cause.