ByBen Collins

BBC Sport journalist

News that Jalen Hurts played a game hours after being diagnosed with a blood clot had already shocked the NFL world.

The Philadelphia Eagles then said their star quarterback will probably miss the rest of the season after multiple blood clots were found in his lungs - a life-threatening condition if not treated quickly.

It raised questions over the NFL's handling of the matter and its general approach to player health and safety, partly because the game in question was part of the league's international series.

Hurts' initial diagnosis was in London, before the Eagles played at Tottenham Hotspur Stadium on 11 October, and he flew back with the team that evening.

What do we know about what happened? Why was Hurts allowed to play and then fly home straight after? And what does it mean for him, the Eagles and the NFL?

Sunday, 4 October: Another player stepped on Hurts' left calf during Philadelphia's defeat by the Los Angeles Rams, although he completed the game.

Thursday, 8 October: Hurts first reported an issue to the team. He trained in full all week and had treatment on Thursday and Friday.

Saturday, 10 October: The Eagles arrived in London in the morning and Hurts visited the Cleveland Clinic that evening. An ultrasound showed he had a superficial blood clot (vein thrombosis) in his calf but he was cleared to play on Sunday.

Sunday, 11 October: Hurts returned to the team hotel at about 3am before playing the full game against the Jacksonville Jaguars. A follow-up ultrasound was recommended within 72 hours and Hurts was cleared for the flight home.

Wednesday, 14 October: After receiving daily treatment, Hurts had another ultrasound, which showed the clot had moved, and he was ruled out of the next game.

Monday, 19 October: Joint statement by the Eagles and Hurts' agent said further tests showed he now has deep vein thrombosis and bilateral pulmonary emboli (multiple blood clots in both lungs).

His treatment will involve blood-thinning medicine and he should make a full recovery but is expected to miss the rest of the season.

Some of the initial reports said that Hurts did not sleep for 36 hours before playing in London, but his agent later confirmed that he slept after returning to the hotel and also at the stadium.

Dr Allen Sills, the NFL's chief medical officer, was in London that weekend and arranged for Hurts to be evaluated at the Cleveland Clinic, an American-owned private hospital which is an official supplier of sports medicine services for the NFL's London games.

The NFL has protocols in place for concussions, emergency preparedness and extreme heat, for games in the US and overseas.

But, speaking at a news conference last Tuesday, Sills explained the league does not have a protocol for situations such as this.

Nevertheless, Sills said that those who dealt with Hurts were "incredibly conservative" and that he had "complete confidence" in how the Eagles handled the situation.

Later that day, the NFL Players Association (NFLPA) called for a full investigation, adding that the NFL "previously informed the union that it did not plan to review the care [Hurts] received".

However, on Sunday the league and NFLPA released a joint statement saying they are "working together to review the matter".

The NFL's next international game is in Madrid on 8 November and the local medical co-ordinator is Real Madrid's chief medical officer, Dr Niko Mihic.

Dr Mihic told BBC Sport that blood clots among athletes are "not that common" and remembers in a previous role it took three visits for a baseball player to be diagnosed with a blood clot, because it is not something immediately associated with sports injuries.

Medical advice on whether to sleep and/or stay active is decided case by case. The same goes for whether it is safe to board a long-haul flight with a blood clot, as Hurts was allowed to do.

"It's not as simple as some people think," said Dr Mihic. "There's an amount of judgement that goes into this. It's like you're stuck between a rock and a hard place, but then you make your call."

As he and the NFL finalise their medical preparations for the Madrid game, Dr Mihic expects them to discuss scenarios such as that involving Hurts.

Asked what the NFL can learn from Hurts ultimately getting blood clots in his lungs, the league's Dr Sills replied: "I don't think you can take that outcome and say there was something flawed about the process.

"Sometimes in medicine we do all the right things and other things develop... but we have a committee that looks at all these cases."

Whatever the outcome of the NFL's joint review with the NFLPA, the league will face greater scrutiny over how they handle players around games played overseas.

Players had a 16-hour flight for Australia's first NFL game in September, while the NFLPA's executive director JC Tretter expressed safety concerns over the quality of the field for the game in Brazil.

There are a record nine international games this year and, although the NFL ultimately wants 16 per season, Tretter added that "the goal has to be growing the game while maintaining the standards our players deserve".

Only Hurts knows how he feels about the way he was treated by his team and the NFL's doctors, but even before this issue there had been talk of the 2025 Super Bowl MVP leaving the Eagles.

Even if he does make a full recovery and returns to action, the 28-year-old will always have to bear blood clots in mind.

"The worst risk factor for recurrent embolisms is having had one previously," said Dr Mihic.

As for Philadelphia, they do not have an experienced quarterback in reserve and back-up Tanner McKee could not prevent them suffering a fifth straight defeat on Monday.

They were beaten 38-21 at home by the Dallas Cowboys to extend their longest losing streak under coach Nick Sirianni, so this could be a long season for the injury-hit Eagles.

Or with the trade deadline two weeks away, this could be the start of a rebuild for a team that reached two of the past four Super Bowls.