Álvaro Carreras has started, and played the entirety of, every La Liga match since he arrived in the summer. With 90 minutes under his belt in each of the opening three, it's clear as day who Xabi Alonso sees as his starting left-back.
Ferland Mendy and Fran Garcia haven't had a sniff of action so far, with Xabi Alonso asserting very clearly what he wants out of his team.
Given everything we knew about Xabi Alonso already, and what we've come to know about him in his Real Madrid entrance, we can safely assume that one Real Madrid player has no future at the club.
Álvaro Carreras made life difficult for Ferland Mendy at Real Madrid
Indeed, the arrival of Álvaro Carreras has left no chance for Ferland Mendy to impress. His time at the club, if it wasn't already, is done.
See, Xabi Alonso clearly prefers attacking full-backs. This is just a change that Real Madrid must adapt to in the post-Ancelotti era, but it's awful news for Mendy.
We know what you may be thinking - Injuries, suspensions, rotation - Surely these three facets will lead to more game time for left-backs other than Carreras.
You'd be right, but Mendy is still out of that conversation.
FBRef lists Fran Garcia as the player third most 'similar' to Carreras, which is great news for Garcia, but bad news for Mendy. If Carreras is ever unable to play, or Alonso simply wants to rotate, it's likelier to be Garcia who gets the nod than Mendy.
And look, fans don't need comparison charts to understand this point. It's clear as day, even with the naked eye; Garcia is better with the ball at his feet, and more comfortable in the opposition's half, than Mendy will ever be.
In truth, it's a miracle Mendy survived the summer transfer window. Real Madrid weren't overly active, and Xabi Alonso needed time to understand his squad, but Mendy is surplus to requirements.
With some worldwide markets still open, it remains to be seen whether Ferland Mendy remains a Real Madrid player for this season. One thing's for sure, he's walking on a very thin tightrope between now and January.
It's not a reflection of Ferland Mendy's talent, either. This must not be misconstrued. Mendy could walk into most European clubs, but his strengths don't lean into Xabi Alonso's personal preferences.