Patriots WR Nelson Agholor took a knee and screamed for the referee to stop a play after realizing his teammate had a head injury

• Patriots receiver DeVante Parker suffered a head injury against the Arizona Cardinals on Monday night.
• Parker's injury appeared to go unnoticed by the officials working the game, as well as the spotter designated to look for head injuries.

Monday night's game between the New England Patriots and Arizona Cardinals was marred by injuries, with both teams suffering significant losses to their personnel throughout the match.

Cardinals quarterback Kyler Murray was forced out of action on just the third play of the game, suffering a non-contact injury that turned out to be a torn ACL that would end his season.

On the Patriots side, DeVante Parker took a hard hit late in the first quarter that caused him to stumble to his feet getting up.

At this point, Parker should have been removed from the game immediately by a spotter designated to look for head injuries throughout the game.

According to the new rules agreed to in the wake of Dolphins quarterback Tua Tagovailoa's disturbing concussion suffered earlier in the season, players who show "ataxia," defined as "abnormality of balance/stability, motor coordination or dysfunctional speech caused by a neurological issue," would be instantly deemed a no-go for the rest of the game.

But despite Parker's stumble, play looked likely to continue, indicating that the spotter in the game might have missed the symptoms.

Thankfully, one person didn't miss Parker's need for medical attention — his teammate Nelson Agholor.

Once he recognized the situation, Agholor dropped to one knee, hoping to indicate to an official that a stoppage was needed. When that didn't work, he waved his arms and yelled at whoever would listen to shut things down until someone could get to Parker.

Eventually, play was stopped, as the Cardinals challenged the ruling on the field of a completed catch. Parker was attended to, and later ruled out of the game due to a head injury.

Fans following the game on Twitter praised Agholor for his heads-up play to help his teammate.

On Tuesday, Parker thanked Agholor in an Instagram post, and took a moment to call out the NFL's failure to spot the injury as well.

The Patriots have a short week this week as they prepare to take on the Raiders on Sunday.