Ryan Christie will undergo surgery after Celtic confirmed the midfielder suffered "multiple facial fractures" in his collision with Aberdeen's Dom Ball.
The 24-year-old was poleaxed by the Dons defender following a sickening clash of heads during Sunday's Scottish Cup semi-final.
Ball was shown a second yellow card by referee Craig Thomson after smashing into his opponent's cheek.
Christie had to be carried from the Hampden pitch on a stretcher wearing a neck brace but later released a picture on social media giving the thumbs up while sporting a black eye.
However, Parkhead chiefs say they are not yet at a stage where they can predict when he will return as he prepares to go under the knife - placing his participation in next month's Scottish Cup final in serious doubt.
A statement posted on the Hoops' website said: "Ryan is scheduled to undergo surgery on Thursday. We are not able at this stage to give any specific indication on a timescale for his return to action but, of course, everyone at Celtic wishes Ryan all the best for his full recovery."
Meanwhile, Celtic's European Cup-winning captain Billy McNeill is to receive a prestigious award from Spanish club Athletic Bilbao in tribute to his "faithful service" to Celtic.
Bilbao's 'One Club Man Award' was set up four years ago with the aim of honouring players whose career with one team represents the values of "commitment, loyalty, responsibility, sportsmanship and respect".
Now 79, McNeill spent his entire career with the Hoops, with his crowning achievement coming in 1967 as he led Jock Stein's team to victory over Inter Milan in the European Cup final.
His tally of 790 competitive appearances for Celtic remains a club record.