It’s hard to get a good read on what exactly caused the collision of Ramos’s arm and Karius’s head, and it’s especially difficult to divorce the incident itself from the context of the match and the players involved. Ramos has a well-earned reputation for arguably overly physical play that stretches the rules. Most prominently, earlier in that very same match Ramos bundled into Liverpool star Mohamed Salah in a takedown that injured Salah’s shoulder and saw him subbed off soon after.

But while Ramos does have a history of dirty play, it does appear that in the incident in question Liverpool defender Virgil van Dijk pushed Ramos in the back right before he careened into Karius. Whether van Dijk’s push was in fact enough to send Ramos stumbling into Karius or if the Spaniard exaggerated the force to get a hit in on Karius is impossible to tell.

What is clear is that doctors believe that hit—which came only a couple minutes before Karius rolled the ball straight to an opposing player and gifted Real Madrid a goal—was enough to give the keeper a brain injury. Here’s what the doctors’ statement says about the test:

On May 31, 2018 Mr. Karius underwent a comprehensive examination by Dr. Ross Zafonte and Dr. Lenore Herget in Boston at Massachusetts General Hospital and Spaulding Rehabilitation Hospital.

After carefully reviewing game film and integrating a detailed history – including his reported present and immediate post-contact subjective symptoms – physical examination and objective metrics, we have concluded that Mr. Karius sustained a concussion during the match May 26, 2018.

At the time of our evaluation, Mr. Karius’s principal residual symptoms and objective signs suggested that visual spatial dysfunction existed and likely occurred immediately following the event. Additional symptomatic and objectively noted areas of dysfunction also persisted. It could be possible that such deficits would affect performance.

This info poses more questions than it answers. Anyone is free to speculate about whether this explains and/or justifies Karius’s two blunders that directly led to the decisive goals in Madrid’s 3-1 win, or about Liverpool’s motivations for soliciting the exam and doing so in Boston (the team’s owners are based out of that city), or any of a number of other considerations in light of the news. What isn’t up for debate though is that soccer needs to take head injuries much more seriously than officials currently do, for the sake of the spectacle itself and especially for the players.