The ready smile was still in evidence but the mood wasn't quite as bubbly as it had been during last month's British Open. Justin Rose is discovering, no doubt, that things are a lot more serious now that he is playing for pay.

He remains no more than a callow youth, having celebrated his 18th birthday on July 30th. Still, the maturing process has been subjected to a fairly dramatic acceleration in the weeks following Royal Birkdale.

Rose's only previous visit to this country was as a member of an ill-fated England line-up in the European Amateur Team Championship at Portmarnock last year. And he is back, making his debut at The K Club, on a sponsor's invitation into the £1.5 million Smurfit European Open.

"It's a great course," he said after a practice round yesterday. "I thought the fairways were a decent size but your irons have to be precisely hit so as to keep the ball under the hole. It's not that the greens are terribly fast but there are some big, breaking putts that require local knowledge."

Not having played in the USPGA Championship last weekend, he was in a position to make an early arrival here on Monday. But several leading competitors, including Lee Westwood, Per-Ulrik Johansson, Thomas Bjorn and David Carter were not far behind him, getting here yesterday.

The challengers also include Christy O'Connor Jnr, who celebrates his 50th birthday today. He is now looking to a career in senior ranks, with a debut in the PGA Seniors at The Belfry next week. But the significance of the prize money at stake this weekend hasn't escaped him.

"A top-seven finish (seventh place is worth £37,500 Stg) would get me a card on next year's regular tour," said the Galwayman, who has already earned £14,440 for 162nd place in the Order of Merit.

Meanwhile, when Johansson retained the title 12 months ago, he seemed to experience little difficulty in shattering the par with rounds of 68, 62, 66 and 69. But reigning Murphy's Irish Open champion, Carter, sees no chance of a repeat of that scoring.

"The rough is very definitely rough and the fringes around the greens are a lot tighter than I remember them last year," said Carter, who finished in a share of fifth place after a sparkling, closing 36 holes of 134.

He went on: "There's no way anyone is going to get near last year's scoring. The quality of the course has improved significantly in the last 12 months but it has also become a lot more difficult. I think something in the region of 12 or 13 under par should be enough to take the title."

Carter is challenging for a high-profile double of the Irish and European Opens in the same season. And, surprisingly, it has already been achieved twice - by Ian Woosnam in 1988 and by Nick Faldo in 1992. "It would be fantastic to do it again," mused Carter, who won at Druids Glen after a play-off with Colin Montgomerie.

He went on: "Winning the Irish Open did wonders for my mental attitude to the game. And, looking at the two courses, I would rate Druids Glen as the more difficult off the tee but this presents a tougher challenge for approach shots."

Since his Irish Open triumph, the 26-year-old native of Johannesburg has shown somewhat moderate form, including a missed cut in the Dutch Open. "It was a mistake to go there," he said. "I felt I had done well to make the cut in very difficult conditions at Birkdale and I should have taken a break.

"But I've since put things right by opting out of the German Open. It means that I've been resting for the last two weeks and I'm now anxious to get back playing again."

Rose also wants to play, but for a sharply contrasting reason. "I need to make about £55,000 to secure my Tour card for next season," he said simply. "With invitations to the next four tournaments, I am now starting a run of five-in-a-row. It's nice to be getting into a rhythm."

Since his exploits at Birkdale, where he performed spectacularly in sharing fourth place behind Mark O'Meara, congratulatory letters have come flooding in. "They would run to about 1,000," he said. "So far I've managed to read only about half of them and much of the last two weeks has been spent in writing replies."

In his only two tournament appearances since the Open, Rose missed the cut in the Dutch Open (77, 65) and the Volvo Scandinavian Masters (71, 75) in successive weeks. But he is looking forward to the chance of creating a continuity while securing his future in the process.

"I played quite a few tournaments as an amateur and though it is a bit more serious to be doing it as a pro, it feels pretty much the same to me now," he said. "The work ethic in professional ranks is very good.

"During tournaments, I find that I work harder, especially on my short game, since the facilities are so much better. That is certainly the case here this week, which makes it a real bonus."

Did he think he could win this season? "I feel if I got the opportunity to win, and I know it's easy to say this now, I don't think I'd be scared of going all the way," he replied. "It's a matter of getting the breaks." Then, after a short pause, he added emphatically: "Yes, I think I can win."