Brendan Rodgers announced in his most recent pre-match press conference that Callum McGregor is going to be out until after the international break.
The Captain picked up a knock against Dundee that resulted in his missing Celtic's trip to Tynecastle. His absence was noticeable as the Hoops fell to a dismal 2-0 defeat against Hearts that saw them miss the chance to leap back to the summit of the cinch Premiership once again.
Injuries are impossible to prepare for, but the ramifications of missing a player who is so often playing 50-60 games a season could potentially be catastrophic for Celtic.
The Captain has some pain in his hamstring/calf area, and an inconclusive scan rules him out of tomorrow's Scottish Cup clash, and Rodgers will have to be cautious with McGregor's recovery as risking aggravating the injury is something that Celtic simply cannot afford.
With the stakes raised for every game given how close the title race is being run, someone has to step up in the Captain's absence, but who should take Callum McGregor's place in the team for the next few fixtures.
Paulo Bernardo
Paulo Bernardo has been a consistent feature for Celtic over the course of this season, and opinions seem to be split on the Portuguese loanee.
Much like McGregor, some of the strongest aspects of Bernardo's game are his pressing and passing, one of the main reasons why Brendan Rodgers preferred to use Bernardo in the Champions League Group Stage instead of David Turnbull.
He had endured a slow start to the season, with many suspecting that he may have been heading back to Benfica in January, but he began to hit form just before the winter break.
He started to show more attacking quality in his game, and with Tomoki Iwata doing most of the defensive work, this would allow Bernardo to roam forward and showcase more of his attacking play over the next few weeks.
An all-rounder, he seems like the player who will most likely slot into the Celtic midfield alongside Iwata and Matt O'Riley, although the manager could look to do something different that would throw us all off.
Daniel Kelly
Daniel Kelly has emerged over the last week or so as an option in this Celtic team.
His name had appeared on the bench a few times, and he made his debut for the Hoops against Buckie Thistle in the Scottish Cup. He really took his chance though when he was brought on from the bench against Dundee, replacing McGregor who had suffered the injury that has him currently sidelined.
He scored an incredible goal against Tony Docherty's side as he curled a well-placed effort beyond the keeper on his weaker foot, and Rodgers once again trusted him at Tynecastle as he brought him on from the bench.
Injuries should open the door for opportunity at Celtic, and the injury to the captain could provide the opportunity for the 18-year-old to get a few more appearances under his belt with the first-team.