As learning curves go, Frankie Sheahan's has been one of the more curvacious. There's been the Irish schools, the Irish under-21s, Cork Constitution, and most of all three years understudy to Terry Kingston, Mark McDermott and, of course, Keith Wood in turn at Munster level. Now 23, noone was straining at the leash this season quite like Sheahan.

It's showing too. Last week Sheahan wouldn't have been unworthy of that dubious man-of-the-match award for his tour de force in the coalface against Castres. Aside from perfect throwing, and his eye-catching ball carries and tackle count, as Sheahan points out there was more going on than the eye could see. "Every single scrum was like the only scrum in the match. You had to put everything into it."

"If you took your eye off the ball you were caught, but though they caught us in one or two we didn't really. They got three penalties on us, we got two penalties on them, and we both wheeled each other around. Jeremy (Castres captain Jeremy Davidson) had told us over the years that the scrum was God in Castres. It was a good confidence booster, lock out the crowd and carry on with your own thing."

Sheahan, understandably, has never enjoyed a steady run of games so much, but through all the ecstasy of winning the interprovincials again and winning their opening couple of European Cup games, the hooker can identify with the replacements.

"They're so happy on the one hand, they're jumping up and down straight after, but then when things calm down they reflect and you can tell they're gutted really in one way. When you're not getting a trot even for two minutes you just don't seem a part of it."

Therein speaks the voice of experience. Sheahan, understudy to Keith Wood in all of Munster's 15 competitive games last season and eight times at national level, was limited to bit parts with his province until replacing Wood for the second-half of the semi-final against Toulouse. He won his first cap as a half-time replacement in the game against the US on the end-of-season Americas' tour. That's a lot of benches, a lot of splinters for a young man in a hurry.

Nor was it something he had bargained for. After the years as understudy to Kingston and McDermott, last season was supposed to have been his big breakthrough year. Although ultimately it was, in a way, initially he admits he didn't take kindly to the prodigal return of the bald wonder.

"When he came home I was absolutely gutted. I felt like I was last to hear the news. My mother heard it on the radio and rang to tell me. I kind of felt betrayed or something. To be honest I looked into all my options. I got on to an agent and I was going to take off. I was fed up with it."

"But in fairness I met Woody at an Irish fitness session, he appreciated I was a bit peed off about it and he was very good about it. Basically he said `we can go two ways, we can help each other or not talk to each other' and cited the example of himself and Barry Williams on the Lions tour, when they were good buddies."

That's how Wood recalls it too. "We had a good chat, no bullshit and we worked hard together. We were supportive of each other all along," says the Irish captain, who likens Sheahan to Terry Kingston. "He's tough, he's aggressive, his basics are pretty good, he scrums pretty well, his line-out's good. He's a good traditional hooker. This is going to be his first full season and he'll learn an awful lot this season in a different way."

Sheahan was particularly impressed by Wood's mental hardness. "He's a very calm, confident character. I learnt a lot from him in that way. It wouldn't be his play as such, it would be more his attitude, that's very important too."

Sheahan's primary concern over Wood's homecoming was that it would stymie his national prospects, but as it transpired he was promoted to Wood's understudy within the Irish set-up after injury ruled out Ross Nesdale. And so the tutelage was extended, even taking in a former All Black hooker, Warren Gatland, as his national coach.

Of all the tips passed on to him, Sheahan recalls the summer tour when he had been hitting his jumpers but felt he wasn't getting a spiral on it. "It has been annoying me for three or four weeks, and at the next session Gats said `move your (throwing) hand back an inch and throw it to me'. Bingo. Such a small thing but throwing can be a little like golf, there are so many technical things. He can gave me tips on throwing to the back, on taking a bigger step, or watching the arch in my back. All very technical stuff and on the scrummaging as well, feet positioning and where you aim on the other front-row. A lot of people talk about the props in terms of the scrum, but all the pressure's going through the hooker."

Not that the year wasn't without its low point, and in a high-profile way. Looking back on his infamous headbutting of an Irish fan in London the night of Ireland's heavy defeat, Sheahan admits: "I over reacted. No-one died at the end of the day and there's thousands of things worse that can happen to you. A death in the family, something going wrong with your health, your girlfriend breaks-up with you. But it was a mistake and you can only learn from your mistakes."

He claims he actually coped well with the fall-out, even making it into something of a joke by keeping some of the cuttings, getting a kick out of headings such as "Bad Boy Sheahan Escapes Gat Axe."

"It's a good talking point. To be honest it suits me down to the ground if people are talking about me. I just go out and play my own game, hit my darts and all I want to do is win matches basically and keep improving. And so far this season I've learned so much. There's no substitute for experience really."

"I learned a lot from Keith last season, but I'm a different player to him. I don't think there's a hooker in the whole world who's going to play the game like he does. I mean Keith could play in the back row - you never know too, stranger things have happened, he could end up there. I'm more the traditional hooker. I try to model myself on Sean Fitzpatrick, just do my foraging, work hard in the tight or whatever, and that suits a lot of games too. Of course I'm going to take a few balls on, but I'm not going to be out on the wing or full back, Hoggy (Anthony Horgan) and Dominic (Crotty) and these guys can do that. That's not to say if I had the talent of Woody I wouldn't play like him. He's a great player."

At 23, and after all the learning curves, what Sheahan needs now is games to further his development, for that is the best way of learning. And, who knows, it could be that he'll get even more games were the Irish management to re-instate the more experienced and recuperated Nesdale as Wood's understudy with Sheahan being farmed out to the A side. That might seem like a step backward but in another way, coupled with his establishment in the Munster team, could be seen as a couple of steps forward.

Whatever about all that, Sheahan is merely focusing on playing for Munster, keep on winning with them and keep on learning. All part of the curve. The best thing is, his best years are still ahead of him.