Billy Vunipola can scarcely believe he is in the England rugby squad alongside brother Mako just over a year after being hospitalised with a rare viral infection and a freak hot water bottle accident.
The Wasps No 8 missed four months of last season as a result of the infection but the 20-year-old has since played a key role in the club's fight for Premiership survival this term and the uncapped back-row forward is now in the same England squad as Mako, an already-capped England front row forward off the bench.
"I was in hospital for quite a long time, so to be sat here now (alongside Mako and in the England squad) is quite unbelievable," said Vunipola, who will join his brother at Saracens next season.
"I had discitis. I got pneumonia and then I burned my back with a hot water bottle so I was in there for quite a bit longer. I fell asleep on the hot water bottle and forgot to put the outer cover on. When I came out of hospital I had to go on antibiotics and go in for regular checks.
"I am not sure I am about to be an England international just yet, but the prospect of it is really exciting," he added.
However, Mako is set to make his first Test start against Italy on Sunday in place of Joe Marler as England continue their bid for a first Grand Slam since 2003.
The powerful brothers, sons of the former Tonga captain Fe'ao, have long been tipped for Test honours, although their diet has not always won the approval of fitness coaches.
"I phoned Billy when he was in hospital to ask if he was okay. When I went down to see him he asked me to bring him some food so I brought him KFC (takeaway fried chicken)," Mako said.
"I walked straight through the hospital with it and the nurse was like 'I thought you were supposed to be rugby players'!"
Nevertheless their fitness bid has paid off, with Mako saying: "We were bigger than most of the boys but we felt our weight was holding us back a bit. We knew the work we would put in would give us a better chance (of making it at the highest level."
England coach Stuart Lancaster is due to name his side to play Italy on Friday, with fly-half Toby Flood set to replace the injured Owen Farrell in one of several changes to the side that beat France 23-13.