Shane Duffy is the type of character who will just get back up again when Stones are thrown at him.

Albion's defensive rock survived life-saving surgery as a teenager when his liver was sliced open in an accidental clash with a goalkeeper during training with the Republic of Ireland.

The opponents at Wembley in the semi-finals of the FA Cup offer further evidence of the resilience and determination which has made Duffy such a key figure in the Seagulls' success alongside Lewis Dunk.

John Stones (below), now a rival with Manchester City, was once a team-mate at Everton.

The Argus: Duffy made Premier League and Europa League appearances under David Moyes at Goodison Park. His prospects waned when Roberto Martinez took charge and preferred the more cultured attributes of Stones.

There are no hard feelings. "If I see him (Stones) I would say hello, stuff like that," Duffy said. "A text here and there. Nothing like every single day, but I'll drop him a text if he's done well.

"He was close to us when we were at Everton. I don't know if he'll play. It will be good to see him anyway."

Duffy also bears no grudge against Martinez. Did the Spaniard leave him with a point to prove?

"Not really. I don't think I was good enough to break in at that time," he admits. "I think it was my time to leave. Sometimes you just get a feeling where you have come through as a kid and you're just never going to really break through.

"They were signing anyone they wanted and I thought I needed to make a career for myself. It ended up being the right decision, because I could have just stayed there being stale, getting a game here and there.

"It's not what I wanted and I had to drop down, play a lot of games somewhere else and then work my way back up. At the moment it's been the right decision so I'm happy with that."

Loan spells with Scunthorpe and Yeovil during his time at Everton were followed by a move from Merseyside to Blackburn before Albion bought Duffy for a bargain £4 million three summers ago, after just missing out on promotion.

The Argus: They made amends in his debut season and he has now accumulated over 100 appearances, more than at any of his other five clubs - he also had a loan stint at Burnley.

"I didn't know that," Duffy, 27, said. "I love it here. It's been great since I've been here. We got promoted and then stayed up. This season we've got to the semi-finals of the FA Cup and we're battling to stay in this league again.

"I'm delighted to be here. It's one of the best clubs I've been at and it's a club on the way up. It's always progressing and they have shown faith in me and improved me a lot. I am thankful to the club and I have no other reason to leave unless they tell me!"

Duffy joined Albion a couple of months after he was sent-off for a professional foul on Antoine Griezmann, whose two goals for France knocked the Republic of Ireland out of the last 16 of the 2016 Euros.

The Seagulls were not dissuaded by a cocktail of red cards and own goals towards the end of his two years at Blackburn.

The Argus: Duffy believes he is a much better player now. "Ten times probably, just purely from playing games," he said. "Early on in my career I made a lot of mistakes in games where I would get punished. I just had to stop making them. I don't feel I make as many mistakes in games now where we are punished by goals.

"That's just consistency and playing every week. I have just got a lot more mature as a centre-half. If I have to smash it in the stand I will instead of playing out and doing something stupid."

Game after game, Duffy and Dunk are confronted by some of the best strikers on the planet.

City have beaten them all three times Albion have met them in the Premier League and Sergio Aguero has scored against them twice.

"It's difficult because I just don't think it's him," Duffy said. "He is very good all-round, does a lot, but I think it's the players around him he needs.

"That's probably more dangerous than Aguero, because if you just stick around, he needs players to link up and play him through.

"Who ever plays, even Jesus (below) when I've played against him the last two times, I thought his movement was frightening.

The Argus: "He doesn't score as many goals as Aguero but his movement is even better. It's so difficult. It's the players around them that are the ones you really have to stop and hopefully that's our game plan, to stop those players having so much time to find the Agueros and Jesuses.

"Hopefully we can be compact and send them out wide and then just try to defend crosses and stuff."

There are tougher challenges than dealing with City's global stars. The six-inch, L-shaped scar across Duffy's ribs and waist from his liver operation is a constant reminder of that.

"At one stage I didn't think I would be alive, never mind playing in a semi-final," he said.

"I thought about that as well when I was at the Euros. You've got to embrace these moments. You might not be here again."