Mike Brown may have played his last match for Harlequins after being sent off in an astonishing 48-46 English Premiership win over Wasps on Sunday that was only decided by the final play of the game.
The 35-year-old Brown, England's most-capped full-back, saw red four minutes into the second half after he stepped backwards and stood on the head of Tommy Taylor, who was holding him at a ruck.
Wayne Barnes, a hugely experienced Test referee, reviewed the incident on the big screen before ordering Brown off the field at the Twickenham Stoop.
Earlier in the match, Brown -- who played the last of his 72 internationals in 2018 -- was sin-binned for a deliberate knock-on.
A stamp to the head carries a minimum six-week ban and that may mean Brown's career with Quins has now come to an abrupt end given he joins Newcastle next season.
There are only four rounds of matches left in the regular Premiership season.
If Brown, who has been at the London club for 16 years, is to play for Quins again he must hope they qualify for the play-offs or that officials decide there are grounds for reducing his suspension.
Harlequins currently occupy the fourth and final play-off place.
- 'Outstanding Smith' -
Despite Brown's exit, Harlequins won a remarkable match featuring 12 tries.
Marcus Smith's last-gasp score saw him go over just as the clock passed 80 minutes beore the rising star added the decisive conversion.
Afterwards, Harlequins assistant coach Adam Jones suggested Brown could yet turn out for the club again.
"In those situations when you're being held in it can look a lot worse than it was," he said. "There was a lot going on as it happened.
"Let's wait until next week and see what happens. He's gutted. I'm sure the club will go balls-out to defend him as much as we can."
Meanwhile Jones, a former Wales and Lions prop, said 22-year-old uncapped fly-half Smith would have made 50 Test appearances by now if he were a Welshman.
Smith's late converted try was part of a 28-point haul witnessed by England coach Eddie Jones, who was in the stands at the Stoop.
With the likes of England captain Owen Farrell involved in the British and Irish Lions tour of South Africa, Adam Jones believes England should call up Smith for their matches against the United States and Canada, if those fixtures are not scuppered by Covid-19 restrictions.
"He's a great goal-kicker, his line kicking is outstanding and his game management is outstanding," said Adam Jones.
"He's got to be on the England tour. He's got to be the future. He's a young kid but is growing all the time.
"It's a pleasure having an outside-half like that. I've got to be honest, if he was Welsh he would have 50 caps by now. He's very much of the Welsh outside-half ilk. Hopefully he gets picked in the summer and I'm sure he'll do a grand job."
Wasps boss Lee Blackett was left lamenting his side's failure to make their man advantage count.
"You can't come to the Stoop and score 46 points and lose the game," he said.
"It wasn't just the last 10 minutes, it was throughout the game -- our defence fell off a cliff."