After two initial rejected bids from Celtic, Arsenal finally signed the highly-rated Kieran Tierney on deadline day.
The North London side have been in the market for defensive reinforcements all summer and Tierney will add a new dimension to the Gunners’ backline.
Emery was faced with the important task of fortifying his defensive contingents and the 22-year-old was one of the additions alongside David Luiz in a bid to improve his defensive “situation”.
Arsenal were the highest conceding team in the top six last term and perhaps a little more stability this time can save the Gunners some points and earn them a prestigious spot back in the Champions League.
Tierney has been tipped to be a regular starter for the Gunners, which leaves Emery with a big decision to make regarding the two first-team left-backs currently at his disposal.
However, the 22-year-old is currently out injured and is expected to resume training in October hence Emery has had to use one of his available options in Sead Kolasinac and Nacho Monreal.
The former had been a subject of a security issue since he and teammate Mesut Ozil were involved in gang-related attacks in London.
The Bosnian has now missed the opening two games of the season as a result, leaving Monreal to fill the spot at the moment.
Emery could potentially be facing a selection dilemma as Kolasinac is now fit and ready to play – more importantly what happens when the trio of Tierney, Monreal and the Bosnian are all fit and available for selection?
The long-serving Nacho Monreal has enjoyed some great times as a Gunner. However, at 33-years-old, he is very much in the twilight of his career. And with one year left on his contract, it’s safe to say it’s almost time up for him at the club.
Yet, he remains one of the club’s most consistent and reliable defensive options.
A much younger Kolasinac at 26 and a developing Tierney at 22 seem like the ideal candidates to tie down the left-back position on a long-term basis.
This statistical analysis gives a comparison between the Bosnian and Kieran Tierney. Who should Emery be looking at for his first-choice left-back candidate?
Monreal is ageing and at 33 he would ideally be “ignored” in this context.
Kieran Tierney easily comes out on top in this aspect.
The Scot averages 1.7 tackles, 2.2 interceptions and 2.5 blocks per game which is by far better than Kolasinac at 1.4 tackles, 0.4 interceptions and 1 block per 90.
The 22-year-old youngster seems to be a more stable option defensively.
While they both have tendencies to roam forward, Sead Kolasinac, on the other hand, is far more prone to defensive errors and lapses in concentration.
The Scottish international also boasts a better block average at 0.2 blocks per game which narrowly edges out Kolasinac’s 0.1 per game.
Ultimately, it would seem like if Emery needs a more reliable and organized backline, Kieran Tierney should easily be getting the nod ahead of Kolasinac.
One quality the Scot seems to lack though is Kolasinac’s aerial prowess.
Tierney’s success rate in the air compares less favourably to that of Kolasinac which could perhaps be a slight cause for concern.
In terms of success rate in defensive duels, both players rank very close with around a 25% success rate.
For aerial duels won though, Kolasinac is by far the better candidate. His 39.3% win percentage in the air betters that of Tierney at 25.3%.
A huge part of the role for a modern day wing-back is their ability to push forward in attacking sequences and create goal scoring opportunities for his team-mates.
Last season, Tierney registered five assists across all competitions. This fell short of the impressive seven registered by Kolasinac.
Reassuringly for both Kolasinac and Tierney, their Expected Assists totals coincide with their assist numbers indicating that they were good value for their totals last season and have no problem in creating high quality chances for their team-mates.
Statistically, it would seem the Bosnian is perhaps a better choice going forward.
Sead Kolašinac compared to defenders in the Premier League this season (per 90):
• Most 'big chances' created
• Most touches in opposition box
• Most open play chances created
• Most errors leading to shots
— Squawka Football (@Squawka) January 11, 2019
Kieran Tierney’s Strengths
Tierney’s ability to create quality chances for his team-mates is illustrated by his impressive underlying attacking numbers.
A strong carrier of the ball, he is averaging 2.76 progressive runs per 90 minutes – this comfortably betters the output of Kolasinac at 1.66.
In fact, that average would have ranked him third in the Premier League last season for left-backs who have started 15 or more matches, bettering the likes of international team-mate and Liverpool left-back Andy Robertson.
Not just good at driving forward with the ball, he also proves fleet-footed when faced with challenges from opposition defenders and averages 3.19 successful dribbles per 90 minutes, dwarfing the average of Kolasinac at 1.27 per game.
Tierney also boasts a better pass tally per 90 with a better success rate too.
His average of 64.74 passes per game with a success rate of 82.31% betters that of Kolasinac at 43.74 passes per game and a lesser success rate of 79.1%.
Tierney’s ability to get on the ball more frequently and attempt more progressive passes forward without depleting his overall pass success rate is a standout asset for the Scottish international.
Last season, only the Premier League’s top three sides could better Arsenal in terms of the highest ball possession average.
Additionally, the Gunners ranked top in the division in terms of progressive passes. Therefore certainly in this regard, Tierney would be a logical acquisition who would fit well within Emery’s philosophy.
Overall, it’s easy to see why Emery is keen on bringing Tierney to the Emirates. He is still young but nevertheless, illustrates a striking attacking prowess that could serve Arsenal extremely well in the coming seasons.
At 22, the Scot still has many years to improve and could be a bargain buy for his quality and potentials in the nearest future.