Collingwood veteran Jeremy Howe has been knocked out after a sickening head clash in the opening minute of Thursday night’s loss Hawthorn.

Howe was sprinting towards a loose ball on the wing as Jai Newcombe came from the other way.

WATCH THE VIDEO ABOVE: Jeremy Howe knocked out in sickening head clash.

Know the news with the 7NEWS app: Download today

Howe got to the ball first, but the pair clashed heads in a sickening collision.

The defender lay motionless on the ground as the game was promptly stopped seconds later.

Newcombe was able to get to his feet, but went down to the rooms for further assessment. He was later given the all clear to resume playing.

Howe, meanwhile, was taken from the field on a stretcher as a hush fell around the MCG.

“Just a big head clash and he was out straight away, the umpires did the right thing and stopped play immediately. All care needs to go to that man,” Kane Cornes said.

Howe was able to move his arms in a positive sign.

The incident happened right in front of the Collingwood bench.

“Pretty emotional for the Collingwood bench as well, it happened right in front of them, a player they love,” Cornes added.

“Seeing your teammate go down like that right in front of you is pretty stressful.”

Howe was later taken to hospital.

“The latest word from the Pies rooms is the ambulance has arrived and he will be taken to hospital,” 7NEWS chief AFL reporter Mitch Cleary said at quarter-time.

“A lot of Collingwood players were visibly rattled by that incident in the first few minutes of the game, a lot of consoling was done at quarter-time.”

Collingwood football boss Charlie Gardiner provided a further update to Channel 7 at half-time.

“He is doing OK, he was responsive in the rooms and walking around,” he said.

“We think he is OK. He has headed to hospital for some precautionary scans, but we are really hoping he recovers from this.

“He was non-responsive for a little while and we were all worried about him, but once the doctors got him down to the rooms, he was up and walking around.

“I don’t think there are any other concerns, they just want to take every precaution possible.”

Howe was returning to the side after missing the past three with a groin injury.

The 35-year-old’s absence is a major blow to the Magpies’ hopes of securing an all-important top-four spot.

The 64-point loss was Collingwood’s fourth defeat from their past five and Howe will certainly miss next week’s blockbuster clash against Adelaide and their vaunted three-pronged tall forward line.

The fan favourite recently opened to Hamish McLachlan on Unfiltered about how close he was to retiring after suffering a gruesome broken arm.