Remember when Seamus Moynihan's selection at full back was news? Not that long ago. In the space of a single season, the key position in the Kerry team has gone from worryingly vacant to reassuringly secure.

There was never any doubt that Moynihan's athleticism and devotion would put him at ease in any position, but when Barry O'Shea smashed his knee in early March, there was widespread concern in the county over who might fill the void. Moynihan was good, but the question remained as to whether or not he could hold the ropes to the required extent.

According to Sean Walsh, such a transition involves just a few key adjustments. Walsh was fixed at midfield throughout Kerry's four-in-row run through 1978-81, and then found himself moved to full back when they returned for the three successive titles between 1984-86.

"For me, the big adjustment in moving to full back was the need to be more consistent," he says. "At midfield you would be inclined to go for a lot more ball, but, in the times that you did make a mistake, you could nearly always recover.

"At full back it is totally different. One mistake and there is no time to recover. So I had to learn not to be so eager, and not chase as much ball as I used to. At full back there is a certain amount of ball that you shouldn't go for and it's not always easy to hold off in that regard.

"But the other big thing was concentration, which to me was the hardest part. At midfield you were nearly always involved in the game or what was happening around you, with every kick-out of the ball really, but at full back you mightn't see the action for five or six minutes. So it was a lot easier to lose concentration."

When Kerry manager Paidi O Se found himself in the search for a new full back, the player he referred to as a "prized possession", the choices were thin. Moynihan was also one of the last options simply because his engineering role at centre back was so fruitful to Kerry's attacking movements.

But O Se has also made it known that the full back of today is no longer the orthodox position of the past, not least because of the changes in the opposing full-forward lines. Pace and good footballing skills are now the main components.

Walsh also sees how the position has changed since his day. "For a start, I don't think there is as much high ball coming into the defence as there used to be. There is a lot more movement among the forwards and a more direct build-up. In the past, you would almost always have a tall man at full back, almost always over six foot.

"Now you need a player who can match the pace of the forwards. That's exactly what Seamus has because he is a great all-rounder. So I wasn't surprised at all at how quickly he could adapt. The overall fielding ability is equally important and he has no problems there either."

Overall, Walsh believes the Kerry fullback line has become that bit more settled with Moynihan's introduction. "But one thing I would say - and I know Seamus has said it as well - is that Mike Hassett and Michael McCarthy are two very good players to have beside you."

But although the Kerry captain continues to find new admirers at full back, Walsh does question how much his influence at centre back is missed.

"Even though Seamus has been a great asset to the team since moving in there, personally I think he is missed at centre back. If Paidi O Se could afford to release him from full back then I feel they would be an even better team."

For Walsh, Kerry go into Saturday's replay with another great opportunity of winning: "It sounds obvious, but midfield is going to be the key area. In that I mean the half backs and half forwards as well.

"I feel that Darragh O Se is ready to up his performance again. I think both teams can feel as if they left it behind them the last day, but I'm sure they were happy to get another day out."