One feature of Marcelo Bielsa’s system at Leeds United so far this season has been the variation between two and three central defenders, depending on the number of centre-forwards he expects his side to face.
It’s fair to say it’s been working as Leeds have put themselves right up among the primary promotion contenders, but injuries have started to bite.
Matters already look bleak on the flanks of his defence, with questions to be answered at both left and right back as Bielsa’s thin squad has been stretched to the limit defensively.
At the moment, Leeds can call upon Liam Cooper and Pontus Jansson at centre-half, dropping the hugely impressive Kalvin Phillips in when Bielsa wants to go to a three.
One more central defensive injury could well rob Bielsa of enough senior options to make that switch with as much confidence or regularity.
Phillips may be pressed into more regular central defensive action, but playing in a duo is different to playing in a three.
Conor Shaughnessy and Jamie Shackleton could fill in, but would they be comfortable with the constant chopping and changing as they seek to establish themselves at first team level? It would certainly be a gamble.