England flanker Sam Underhill is an injury doubt for the Six Nations after Bath announced he requires ankle surgery.

The 28-year-old injured his ankle in Bath's 35-34 defeat by Premiership champions Northampton on Sunday.

Bath issued a medical update to say he will "undergo surgery to rectify a new ankle injury" with there being "no set timeframe on his recovery".

Underhill, since his exclusion from England's original Rugby World Cup squad in 2023, has established himself as a regular in Steve Borthwick's starting team at open-side flanker.

He started every game for England after the World Cup in 2023, and played in recent autumn defeats by South Africa and Japan, scoring a try in both.

It was an ankle injury which kept Underhill, who has been capped 40 times, out Borthwick's side's opening two autumn Tests against New Zealand and Australia.

He joins a growing England injury list, with wing Immanuel Feyi-Waboso in danger of missing the Six Nations because of a dislocated shoulder, while full-back George Furbank is struggling with a broken arm.