Marcelo Bielsa knows full well how vital Kalvin Phillips is to his Leeds United team.
In his absence against Brighton, Pascal Struijk filled in in front of the defence, and while he has come in for some criticism as a holding midfielder, it is fair to say some of that criticism has been unwarranted.
What Phillips brings to this Leeds team though, is an almost innate understanding of his role, and as a consequence it makes his function so difficult to replicate. That is less of an indictment of his replacements, more a reflection of his own quality.
Mateusz Klich, Pascal Struijk and Luke Ayling shared the Phillips load against the Seagulls, but in utilising three players to perform the function of one, it lessens the effectiveness of the team as a whole.
Combined with the fact that Phillips' long-passing is one of the strongest areas of his game, filling that role is more than just breaking up play in defensive midfield.
At Elland Road versus Brighton, Leeds United completed 58.6% of their long passes, a 4% decrease on their season average, according to FBRef.com.
Four percent may not seem like an awful lot, but when compared to some of Leeds' most effective performances and biggest wins, the margin stretches wider.
Against Newcastle United, Leeds ran out 5-2 winners, enjoying a 69.5% long passing success rate.
At the Hawthorns, Leeds defeated West Bromwich Albion by five, whilst completing 70.4% of their long balls. In that game Phillips completed 14 of his 17 long pass attempts, while Ayling completed 27/33.
It is clear from these two outings that Leeds are more effective when they can play these long, switching passes to either flank. It quickly helps to refocus the point of an attack and takes multiple opposition players out of the game at once.
Against Brighton, Pascal Struijk managed to complete 80% of his long balls, but falling some way behind the usual success rate was Mateusz Klich and Ayling, managing 30% and 58% respectively.
Take this example in the first half: Brighton's intention was to pack central areas in order to force Leeds wide. They did so by suffocating Leeds whenever they tried to build through the middle.
With Phillips in the team, the ball from Ayling would instead go to the England international, with Klich higher up the pitch, often supporting in wide areas.
Brighton's five-man defence meant that when facing up to Leeds' attacks, they could deploy a five-man horseshoe, with Dan Burn, Adam Webster and Lewis Dunk marking Patrick Bamford and the midfield runner, usually Klich, tracked by one of Ben White or Pascal Gross.
Their wing-backs could step out and press the Leeds receiver out wide, knowing that there was always a numerical advantage in the middle just in front of their goal.
This made it very difficult for Leeds in build-up whose switches of play were shorter and more fragmented, allowing Brighton to shuffle across easier and with less urgency.
It was a tactical performance from Graham Potter's men that worked well. Kalvin Phillips' presence would have improved things, although that alone would not have ensured victory. That said, he would certainly have been able to up the volume of switches played from the holding role, and may have even been better positioned for Brighton's goal.
