Celtic left-back: Who should have the starting jersey? Greg Taylor, Boli Bolingoli and Adam Montgomery analysed

The Scotland international's starting position in the Celtic team looked unlikely to be challenged as Ange Postecoglou continued to use him in his system. However, a shoulder injury has opened the door for others to stake a claim on the left-back spot with Adam Montgomery, Boli Bolingoli and Liam Scales all being given a chance to show what they can do.

When looking at the attributes of a full-back in Postecoglou’s system, the priorities should be athleticism and composure on the ball.

Athleticism is required to maintain high pressure on the opposition. From a full-back, this will come in the form of an intense press on the first touch of the opposition player or in a counter-press high up the field if possession is turned over.

Composure on the ball is also important as full-backs come into the inverted central zones and act as central midfielders for build-up play. They need to be capable of taking the ball in and progressing it accurately to keep up the speed of the attack.

StatsBomb is a good resource for comparing the full-backs although, due to low sample size, it’s hard to compare Scales with the rest. With more minutes this will become easier to accomplish and he has looked athletic and aerially dominant in his brief cameos so far.

Taylor v Bolingoli

When comparing the two full-backs in terms of athleticism it can be seen that Bolingoli has the advantage. He is naturally athletic which makes him more suited to the manager’s high-intensity system. This is primarily seen in a significant increase in pressures and in fouls given away by Bolingoli.  

He is more capable of closing the distance to the opposition and putting them under pressure to regain possession and begin transitional attacks. Due to this, Bolingoli gives away more fouls. However, this is in line with Postecoglou’s high-press philosophy that has seen Celtic rise from almost bottom of the league last season in terms of fouls given away, to third this season.

When looking at composure on the ball the two are evenly matched with only a few differences.

READ MORE: Boli Bolingoli's Celtic expulsion is confusing and clarity is needed - Andy Bargh

They both rank highly in terms of completed passes and deep progressions. Bolingoli has yet to show as much creativity as Taylor in his brief appearances as he adapts to the inverted full-back role.

However, against Motherwell his link-up play with David Turnbull helped create the second goal, so there is some early evidence to suggest he can catch Taylor in xGBuildup. Bolingoli is safer on the ball than Taylor so far, recording fewer turnovers, suggesting he is safer in possession in general.

Taylor v Montgomery

Taylor and Montgomery profile very similarly as full-backs so far.

In terms of athleticism, Taylor is slightly ahead in being able to put more pressure on the opposition though both are significantly behind Bolingoli in this regard.

Montgomery is slightly behind both Taylor and Bolingoli in passing accuracy but shows up well in forward play as regards deep progressions and xGBuildup. Montgomery, like Bolingoli, also gives up possession less often than Taylor.

Montgomery’s main issue is how often he is bypassed by opposition players. His Tack/Dribbled Past perecentage is significantly lower than both Bolingoli and Taylor. This is likely down to his limited experience at the top level, allowing the opposition to take advantage of lapses in concentration and judgement more often.

With his youth spent as a winger, Montgomery has shown signs of being able to progress the ball via his dribbling. He already fairs better than both his competitors in this regard so far.

Conclusion

When focusing on what Postecoglou requires from his full-backs, Bolingoli appears most suited to his system.

He appears to be getting a second chance at Celtic and could look to make the left-back spot his own. His athleticism, coupled with the clear positional instructions from the manager which he may not have experienced before, might make for a good redemption story this season.

With Montgomery, Celtic have a high-potential youth asset that Postecoglou can look to mould into the player he requires.

Taylor, meanwhile, will offer more experienced cover in bigger games than Montgomery can provide at this moment in time. Generally, the left-back position now has substantial depth to it - a major positive going forward.