George Russell said he was in contact with Alex Albons family while the Williams driver suffered medical complications during appendix surgery in Italy.
Russell admitted long-time friend Albons situation had looked very scary at certain stages, after he had suffered respiratory failure while under anaesthetic, through which he was moved to intensive care.
Albon was able to return home the next day after remaining in hospital overnight while he was treated, with a 12-hour period in which his lungs cleared out though this was an unexpectedly fast recovery, as he had been due to be put into induced sedation for two to three days.
Albon then undertook a gradual return to training as he looked to get back in time to race in Singapore, having missed the Italian Grand Prix as a result of his sudden bout of appendicitis.
Albon himself acknowledged that he did not think an outing in Singapore had been on the cards, given the state he had been in, but he will get back behind the wheel of the FW44 during practice on Friday.
Russell thinks Albons return is a measure of his character, though it is a bold choice on his part to throw himself in at the deep end this weekend.
Its definitely audacious to come back for the toughest race of the season having only just recovered, the Mercedes driver said in Singapore, quoted by BBC Sport.
But it just goes to show the sort of grit and determination he has.
Having been in touch with Albons relatives, Russell admitted that it was not plain sailing while he was in hospital, and he had been worried for his welfare.
I was in contact with his family on Saturday night, because it was looking very scary at one point, Russell said.
But its pretty impressive to see how he recovered so quickly. The human body is a scary thing. It just goes to show one minute everything is fine and the next minute everything can change almost totally out of your control. It will be interesting to see how he gets on this weekend.
Williams reserve driver Nyck de Vries is on standby in case Albon has to drop out of contention again, should he not be fit enough to compete this weekend.