James Haskell is in danger of missing the start of England's NatWest 6 Nations title defence after being sent off in Wasps' dramatic 33-28 Champions Cup defeat by Harlequins.
Haskell was shown a red card by referee Roman Poite in the 75th minute for a high tackle on Jamie Roberts and in his absence James Chisholm crossed for the try that settled a remarkable clash at Twickenham Stoop.
Roberts' afternoon was over as the groggy Wales centre departed for a head injury assessment, although he left the pitch with an apology from Haskell that the veteran flanker repeated on Twitter shortly after the match.
"Whats done is done, but just want to publicly apologise to @Jamiehuwroberts," Haskell tweeted.
"Never my intention to hurt another player. Got my height wrong, paid the price, which happens. You know me, never one to do anything subtly. Credit to @Harlequins and apologies to @WaspsRugby fans."
Wasps led 21-0 and having let Quins back into the match, they secured the bonus point as they moved out of sight once more only to endure an alarming late collapse. They can still qualify mathematically, but this defeat all but ended their chances of progressing when they enter their final group match against Ulster on Sunday.
"I think it's over for us now. I said we had to win both of these last two games and probably needed nine points" Wasps director of rugby Dai Young said.
"We'll want to win and if a miracle happens then happy days, but miracles don't tend to happen too much in Coventry."
• Mathieu Bastareaud is under investigation by European Professional Club Rugby after the France international was overheard making an alleged homophobic slur during Toulon's 36-0 victory over Benetton, although he has claimed that he was responding to an insult from second-row Sebastian Negri.