It was a sickening thud when both Boyata and GMS went for the ball and clashed heads.
The force of the collision knocked the Aberdeen star out in mid-air as he fell lifelessly to the ground in a scary moment.
The former Celtic player was stretchered off but did regain consciousness on the pitch.
He was given a standing ovation by the whole stadium as the stretcher took the midfielder away.
Boyata had to have stitches but immediately came back onto the field to set up the winner.
The Belgian’s day was cut short by an injury in the second half.
Speaking about GMS, McInnes gave everyone good news on that front.
#Aberdeen manager Derek McInnes says Gary Mackay-Steven is fine. Says he’s sitting up in hospital. Hoping it’s a straight forward concussion.
— Chris McLaughlin (@BBCchrismclaug) December 2, 2018
It was an honest challenge by both players and just a very unfortunate accident.
We hope to see GMS back on the field soon!
Celtic won 1-0 on the day to be crowned League Cup champions for 2018. Another trophy in the cabinet.