Especially in the early period, they dovetailed so effectively down the flank as Brendan Rodgers created a team with an equilibrium. It gave Tierney the licence to motor forward, constantly providing width. In turn Sinclair had the freedom to take defenders on, move infield and become such a goal threat in supporting Moussa Dembele or Odsonne Edouard.
Now, heading into the 2022/23 campaign, Ange Postecoglou may well be about to create his own fearsome left-hand side. Pace, aggression, energy, verticality, goals and creation.
Jota has been signed up on a five-year permanent deal from Benfica following a hugely successful loan period which saw him hit double figures for goals and assists. Anyone who caught a glimpse of Celtic would have recognised the abundant attacking qualities the winger possessed, from creation to taking on opponents to decisiveness in the final third.
Left-back was a slight issue last season with Greg Taylor having injury issues and Josip Juranovic asked to fill in.
Yesterday saw the addition of Alexandro Bernabei on a five-year deal from Lanus at a cost of around £3.75million.
There should be real excitement amongst Celtic fans at the prospect of the club's first Argentine player linking up with Jota down the left-hand side.
With a season of experience watching a Postecoglou team, Bernabei ticks a lot of boxes in terms of what he'd want in a full-back. In a Copa Sudamerican clash with Metropolitanos, the ball went into their corner then out of nowhere the 21-year-old was over in a flash putting an opponent under pressure and winning a throw-in.
Positive and energetic
He will provide Celtic with plenty of energy with and without the ball.
His key asset which elevates so much of his qualities is his positivity and approach. He wants to engage the game high up the park and progress the ball. During the last calendar year in the Argentine top flight more than half of his passes per 90 minutes were forward.
While, if you were to compare him to his Scottish Premiership contemporaries at full-back, he would rank first for dribbles, progressive runs and successful attacking actions per 90 and second for offensive duels per 90.
Bernabei is very adept in playing under pressure and in tight situations. Even then he will look to be positive which can mean losing the ball in dangerous areas at times. But his attitude is such that he wants to get on the ball and will constantly provide runs forward, over and under lapping to support.
His crossing could be a bit more precise but he is a full-back who is also comfortable getting on the ball centrally and even turning up on the opposite flank.
Going forward he appears more suited to what Postecoglou envisions than Greg Taylor who is still, in this writer’s view, underrated. You only have to see the Scotland international’s performance in the 3-0 win over Rangers to see how competent a full-back he is at that level.
However, Bernabei offers a different proposition and is a more dynamic individual. Now Celtic have two good options at left-back which is the depth the club will want and need going into four competitions next season.
If there is a concern, or more pertinently, an area for improvement for the new arrival, it is defensively. He will leave space in behind but that is the balance which needs to be struck between the attacking qualities he offers and what it means for the shape of the team out of possession.
Bernabei is a willing competitor. Anyone who has witnessed South American football and the Argentine league will know it can be very feisty.
Compared to last season’s Scottish Premiership full-backs, he'd be second for defensive duels per 90 minutes but would rank 40th for success rate and second for fouls.
Celtic had an issue with defending set pieces last season. Bernabei is not necessarily going to improve that. He is, like Juranovic, a diminutive full-back and wins under 45 per cent of aerial duels, albeit a better success rate than Taylor and his new Croatian team-mate.
He is a front foot defender and one to stay on his feet which will stand him in good stead. He gets low and compact in one v one situations but can sometimes be a bit stand-offish. However, he is good at reading the game in terms of stepping in and making interceptions.
Overall the positives far outweighs the concerns about the Argentinian’s game.
Celtic will have a young, dynamic, aggressive left-hand side next season, full of verve, directness and energy.
Spare a thought for the right-backs and wingers of Scottish football.