The assembled press were loitering in the lounge of the bistro at the Oriam where the Heart of Midlothian players, first team, B team and women's team, are fed before and after training. 

One by one or in small groups the first team made their way in following Friday's training session ahead of Sunday's Premiership clash with Celtic. As soon as Frankie Kent entered everyone's attention was drawn to the centre-back. As well as the crutches, he had a brace around his knee that looked like a spare part of a RoboCop costume. 

Naturally, the worst was feared for a player who has emerged as a key figure at Tynecastle Park and can be regarded as one of the best signings made by any club in Scotland this season. 

"The crutches and brace are more just precaution," Steven Naismith said. 

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Kent underwent a scan on Thursday and, according to the Hearts head coach, the knee issue picked up toward the end of Wednesday night's derby will keep him out for "a couple of weeks". It means he will miss Sunday's league encounter and likely the Scottish Cup clash with Greenock Morton a week on Monday. It remains to be seen if he will be available for the Ross County match later this month before the international break. 

"It's disappointing because he's come in, we identified him in the summer as someone we needed and I think it has probably gone as well as possible in terms of our stats defensively, how we have performed, how he has performed individually," Naismith said.

He is not wrong. Kent was exactly the player the team required.

It is nearly a year to the day that Hearts won 3-0 against St Johnstone and had a five-point lead in third. They would lose seven of their next eight fixtures in all competitions. One of the areas where the team had an issue was the lack of a commanding defender. A leader, an organiser, someone who would stick their head on crosses and long balls. Someone who would be in the right place at the right time. With Craig Halkett injured the team didn't have anyone who would naturally step into that role.

Enter Kent. 

Aerial wins, clearances and blocks. He is in the 90th percentile in the Premiership. Essentially, he is better than nine out of 10 centre-backs in those metrics. He is also one of the best for not giving away fouls. A steady, reliable presence who delivers, at least, seven out of 10 performances on a weekly basis. 

Collectively, the team have performed better defensively. On an individual basis, he has been key to that. Rather than bombard the reader with a load of numbers and stats, one particular comparison is telling. Last season, Hearts conceded a combined 28 goals from set pieces and crosses into the box from open play in the league. So far this campaign? Five. 

There was a great example during the draw with Hibs of the 28-year-old's ability to read balls into the box and the aggression to attack. See his starting position. It allows him to measure the flight of the ball.

Hearts Standard:

Then attack it.

Hearts Standard:

Every team in Scotland needs someone who will take control in the box like he does. He fit into the dressing room instantly and has become a leader on and off the field.

Now, with Halkett out injured, the question is: How do Hearts replace him?

"It is really disappointing but it creates an opportunity for the others and I think we have got the cover," Naismith said. "Kye [Rowles] has come back from the Asian Cup, Toby [Sibbick] and [Stephen] Kingsley have played there so we've got enough players to fill in the position."

READ MORE: The two areas Hearts need to improve for Celtic clash after derby disappointment

Hearts podcast Scarves Around the Funnel ran a poll on Friday afternoon asking supporters whether Naismith should go with a back three or keep the back four system that was in operation against Hibs. At the time of writing more than 61 per cent voted in favour of the latter.

It is safe to assume that Kingsley and Rowles would be the favoured pair in such a scenario. Some will be put off by two left-footed centre-backs in a back four. The big issue is opposition teams may find it easier to stop Hearts from building out from the back. While Kent is no John Souttar, he does have good distribution. He played a couple of excellent line-breaking passes against Hibs in the first half. 

Hearts Standard:

Hearts Standard:

Kingsley who has played the right side of a back three will move the ball onto his left. It is completely natural and instinctual. That will complicate matters slightly.

Defensively, the pair complement one another.

Of the two, Kingsley is stronger in the air. Not only does he win more aerial duels but his success rate of 70 per cent (higher than Kent) far outstrips Rowles' 52 per cent. Both, however, play a secondary role to Kent when it comes to competing for balls in the air and taking control so it will likely be on Kingsley to step into that main role and be the leader of the backline. The 29-year-old is having a strong season after a more difficult campaign last season. 

Rowles is very adept at being in the right position to block shots and is strong in one-on-one situations when an opponent tries to take him on. 

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Then there is Sibbick. He has played just twice this year. At right-back against Livingston and alongside Kent as a centre-back in the win at Dundee. He is probably his strongest as the right-sided centre-back in a back three. With Kingsley in the centre and Rowles left-sided centre-back it is a trio that provides a nice balance.

The biggest question over Sibbick is whether he has the pure defensive instincts that the likes of Halkett, Kent and Kingsley have. Having played at full-back, wing-back and in the centre of midfield they are instincts he's not been able to develop consistently. 

Hearts struggled against Celtic with a back four the last time they played the Scottish champions at Tynecastle Park. They were pulled apart both defensively and their shape in general. The team have, however, come on significantly since then, while their opponents are playing more direct with Adam Idah having taken over from Kyogo Furuhashi. 

It is a big question that Naismith will no doubt be playing with. In Kinglsey and Rowles he has two centre-backs who have been more consistent than last season. He'll need them to step up in Kent's absence and lead the defence.