The 25-year-old is a new inclusion in the England Knights performance squad who are preparing for a two-Test series in Papua New Guinea this autumn.
“It was a surprise, I didn’t know it was coming,” said Holmes, who made his debut in 2010 and has more than 150 Super League appearances to his name.
“Paul Anderson, the Knights’ coach, gave me a ring on Monday and the number that came up was one I hadn’t seen before. Usually when that happens I answer and say ‘bonjour’, so I was glad I didn’t do that this time.”
Despite having much of his 2017 season wiped out by a persistent knee problem, Holmes has quietly developed into one of Castleford’s most effective forwards without, until now, gaining the recognition his consistency merits.
“I’ve never really been in representative sides before,” he added.
“I was in a Yorkshire camp when I was about 12, but I never got in the team.
“This is a first of its kind and I’m looking forward to seeing what it brings.”
The phone call from Anderson was Holmes’ first step towards a potential England cap further down the line. He admitted: “I think every sportsman’s long-term dream and goal is to play at the highest level and represent his family and himself.
“You never know, maybe I can one day represent England, but before I can push on to the elite squad I’ll be very happy to represent the Knights and I’m looking forward to Papua New Guinea.
“I’ve never been that far round the world before and it’d be an experience and something different. I spoke to Michael Channing who played there for Wales in the World Cup and he said it was an unbelievable experience.
“I think it’s massive for Papua New Guinea as well. They had a good World Cup and it [the England Knights tour] is an opportunity to build international rugby league outside Australia and New Zealand.”
Holmes’ form for Tigers will determine whether he makes the final squad. Last year’s league leaders are fourth in Super League ahead of Sunday’s regular-season finale at Widnes Vikings, seven points clear of fifth-placed Hull.
“There is a bit of a gap,” said Holmes. “Hull are doing it tough at the minute, but I expect them to come good in the Super-8s.
“There’s no danger of us taking our foot off the gas. We want a home semi-final, I don’t think we are going to catch St Helens – they are probably going to do what we did last year and run away with it – but we want to make sure we finish second so that puts us in the best position possible to right what went wrong last year in the Grand Final. It’s a long way off, but that’s where we are looking.”