West Brom midfielder Jake Livermore admitted he feared the worst when friend Ryan Mason suffered his sickening head injury.
Livermore's former Hull team-mate Mason is making "excellent progress" after fracturing his skull but will continue to be closely monitored in hospital.
The midfielder clashed heads with Chelsea's Gary Cahill at Stamford Bridge in the hosts' 2-0 victory on Sunday and needed nine minutes of treatment on the pitch before being taken to St Mary's Hospital.
Livermore played with Mason at Tottenham and Hull before completing a £10million move to West Brom from the Tigers on Friday and revealed his concerns.
"You fear the worst when something like that happens to any sort of footballer, but it's so close and very fresh in the mind - I only spoke to him a couple of days ago and he wished me well here," he said.
"It's never nice to see any fellow professional (seriously injured), let alone someone you're very close to and talk to on a daily basis.
"I know his family very well. Everyone wishes him all the best, fingers crossed he'll be fine.
"He's from an area close to where I'm from in London so he's not far from me at all. We have many mutual friends as well and I've been in touch with them.
"I obviously haven't bombarded him, but kept in touch with the doctor at the club and a few of the other boys.
"From what we hear, he's making excellent progress. Hopefully that speedy recovery continues. We're all thinking about him that's for sure.
"He's a strong character anyway. I've played with him for a long time growing up and I've no doubts he'll be fine in that respect."
Livermore had the Hull game on television after making his Baggies debut in Saturday's 2-0 Premier League win over Sunderland.
The 27-year-old, though, had to double check the incident and admitted it could have happened to anyone, including him.
"I was back in London with my family. The game was on in the background and I actually missed the incident," he said.
"It was only once I saw half-time and nine minutes of injury time I went back to see what it was.
"There's a good chance I would have (been marking Cahill). There's a good chance that could have been someone else.
"As I say, we are all praying for him this end."
Mason, 25, had surgery in London on Sunday night but Hull confirmed he was recovering well on Tuesday.
A statement released by the Tigers read: "The club can confirm that Ryan Mason continues to make excellent progress after sustaining a skull fracture in Sunday's game against Chelsea.
"He will continue to be closely monitored by staff at St Mary's Hospital over the next few days, whilst also remaining in contact with our medical team to assess his progress.
"There will be no further updates from the club until there are any changes in Ryan's condition.
"We also ask that people respect Ryan and his family's privacy whilst he remains in hospital."
Hull confirmed on Monday that Mason was conscious and communicating having been visited by captain Michael Dawson and three club officials.
Cahill, Chelsea club captain John Terry and assistant boss Steve Holland also went to St Mary's Hospital on Sunday evening to check on Mason's well-being.