The football world is wishing Ryan Mason a speedy recovery after he underwent surgery for a fractured skull.
The 25-year-old was treated on the pitch then rushed to St Mary's Hospital, Paddington, to undergo surgery on a fractured skull. He is in a stable condition but will remain in hospital for the next few days.
A Hull statement read: "The club can confirm that Ryan Mason sustained a skull fracture in our fixture at Chelsea this afternoon.
"He was taken to St Mary's Hospital where he has undergone surgery. Ryan is in a stable condition and is expected to remain in hospital for the next few days.
"Everyone at the club would like to express their sincere thanks for the excellent and swift care given to Ryan by both the Accident and Emergency department and Neurosurgery Unit at St Mary's Hospital.
"A further update will be issued tomorrow (Monday)."
Everyone's well wishes are rightly with Mason to recover, and that is the most important thing, but spare a thought for Cahill as well.
The defender has already wished Mason well after the game before the extent of his injuries were revealed.
"I tried to get on the end of the cross. We smashed heads," he said. "I wish him all the very best."
The Chelsea captain was going for a ball he had every right to go for and there was certainly no intent from him to injure the Hull midfielder. Anyone who has suggested otherwise needs to take a long hard look at themselves.
I'm sure the defender is as upset about the horrible accident as the entire football world. It was something we see every week in football but, on this occasion, it has had such horrific results.
Speaking on Match of the Day 2, former Arsenal defender Martin Keown said: "Our thoughts are with Ryan - its a terrible thing to see on a football pitch, you hope it never happens.
"Of course Gary Cahill was just innocently going for the ball. It was a sickening challenge and let's hope he gets back onto the football pitch again."
Let's all hope Mason makes a full recovery from his injuries. That is the most important thing.