Allen left on a stretcher during Stoke's 5-1 Championship win over Hull City after being tripped by Dan Batty on the stroke of half-time.

The midfielder is set for surgery this week in what represents a huge blow to Wales boss Ryan Giggs.

Euro 2020 will be Wales' third-ever appearance at a major finals.

Allen, 29, played a key role in helping Wales to the semi-finals of Euro 2016.

Stoke manager Michael O'Neill confirmed the news.

"He's ruptured his Achilles, he had to be helped off at half time," he told BBC Radio Stoke.

"You fear the worst, you hope for the player it is not the case, but the news is not what we hoped for and he will need surgery this week.

"It's a huge loss, he's a terrific player and a terrific lad. I am gutted for him, he had so much to look forward to with Euro 2020 as well.

"I am gutted for the player and it takes the shine off a 5-1 victory."