Rob Gronkowski's season is officially over after Monday's MRI revealed that the Patriots tight end has indeed torn his ACL, CBS Sports NFL Insider Jason La Canfora reports.

Gronkowski suffered the injury during the third quarter of Sunday's game against the Browns when safety T.J. Ward went low to make an open-field tackle.

Gronk was unable to walk off the field under his own power and was taken to the locker room on a cart. He left the stadium for the hospital a short time later.

After the game, Ward explained why he went low on Gronkowski: "It was a decision I made just to make a tackle on a big man and unfortunately he got hurt, but if I would've hit up high, there's a chance I would get fined and all that other stuff. I'm just being safe."

Gronk's 2013 season is officially over. (USATSI)

Whether there's an actual increase in ACL injuries or not, the fact remains that, in light of new rules to protect against head injuries, defenders are more likely to go low to make tackles. As we've written several times before, this is the unintended consequences of actions not thought through entirely by the league. Yes, the NFL should thrive for making the game as safe as possible, but drastic changes don't come without ramifications. And the league can't argue that knee injuries were unforeseen because players lamented the possibly as soon as the new rules were announced.

"My intention is never to hurt anyone," Ward continued. "That's not what this game is about. That's not how I play, I hate to see guys go down with any type of injury and I just wanted him to know, whether he accepted it or not, it wasn't an intentional hit to injure him. But we have to play this game, we have to play it the way that they force us to, and unfortunately, we incurred an injury for him."

With Gronk's 2013 season in the books, the Patriots are expected to sign tight end D.J. Williams.