London - England were handed a double Six Nations headache on Saturday after European Champions Cup action saw flanker James Haskell red-carded and No 8 Billy Vunipola suffer another injury setback.

Haskell was sent off in Wasps' dramatic 33-28 defeat by Harlequins for a shoulder-led high tackle on Welsh centre Jamie Roberts.

"Whats done is done, but just want to publicly apologise to @Jamiehuwroberts," Haskell tweeted after the game.

"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."

England open their Six Nations against Italy on February 4 knowing Haskell faces a ban for an offence that appears to be in the mid-range of making a dangerous tackle, which would result in a six-week suspension.

Meanwhile, Vunipola went off at half-time during Saracens' 15-15 draw with the Ospreys after appearing to suffer a wrist injury in only his second comeback game following three months' sidelined because of knee trouble.

"He (Vunipola) has an arm injury which we will obviously explore right away," said Saracens director of rugby Mark McCall.

"I don't know what the extent of the injury is."