I need to learn and cut the errors from my game: Duffy
Mick McCarthy had a firm belief about international football that is backed up by other voices such as Roy Keane: that it takes a player until around the 15-cap mark to really get to grips with the demands of the game at that level.
Shane Duffy isn't even halfway to McCarthy's landmark, only on his seventh senior cap, and he admits that he's still learning at this level.
The error he made at the end of the first half in Sunday's win over Moldova in Chisinau could have gone unpunished in the lower reaches of the Championship, but not at international level. Duffy has played in the Premier League and Europa League for Everton, but his weekly diet of games now sees him face up to clubs like Burton Albion and Rotherham United, and while the Championship is indeed a tough league, international football is different - as he learned to his cost when Igor Bugayev got past him and scored on Sunday.
The player who profited from Duffy's slip may earn his wages at a club (mid-ranking Moldovan outfit Zaria Balta) which no one has heard of but he knows his way to goal when he dons the shirt of his national team with an average of a goal every five games for Moldova.
And Duffy admits he that needs to cut out from his game the mistakes like his moment of sleepiness on Sunday night.
"I don't want to keep using inexperience as an excuse as I don't want to keep making mistakes," Duffy told the Herald.
"I thought I had a comfortable game but one lapse of concentration in the last minute of the first half, that put a dent in the performance but overall I thought it was alright.
"I looked back at their goal, the manager gave me a slap across the head. I just have to get it out of my game.
"I am in good form and confident form but that bad mistake can cost you. I will go back to Brighton, hopefully play in the team on Saturday, and keep my form going.
"Obviously, there was the goal last night but I was happy with the two performances in the last week. For someone who has not played much, it's quite good.
"It was a good week for us, the main objective was six points and the other results went our way.
"I know it's early but every point matters and hopefully we can take the positives away from the two games and move on to Austria.
"Of course, we can go and win in Austria, we have got to play better and have no stupid or silly mistakes at the back."
Figures in the camp like Martin O'Neill and James McClean have bristled at the criticism of the team's displays to date but even Duffy admits that things can get better.
"Performances haven't been outstanding but the results have been and that's all that matters, that's what the manager is trying to get across to us, the most important thing is the three points and that's what gets you to major tournaments," he says.
"These lesser teams, like Moldova, make you play at their level, you have to try and overcome that and this week shows that.
"We have all seen it, we know we can play in the bigg er games. At times on Sunday we played some good football. The first goal was a great footballing goal.
"We have so many good players in the squad, it will come."