Cardiff - Ireland head coach Joe Schmidt hopes he gets the balance of his squad right for the Rugby World Cup, admitting he failed to do so four years ago.
The 53-year-old New Zealander - whose side were affected by injuries and blitzed by a rampant Argentina in the 2015 quarter-finals - said he faced a "horrible couple of days" in coming to a decision on his final 31-man squad.
Ireland will send it to World Rugby on Monday but it will not be made public until September 8 - the day after they host Wales in their final warm-up match before leaving for Japan.
Schmidt will sit down with his fellow selectors on the back of a much-needed win having beaten a second string Wales side 22-17 and partly erasing the scars of the humiliating 57-15 defeat by England the week before.
"I can tell you now, I'm not sure. We need to see what our balance is," Schmidt said replying to how close was he to the final 31.
"Whatever you do there's always a risk you don't quite get it right. I don't think we got it right last time (in 2015).
"It's a horrible couple of days. For those players who miss out it's going to be a real body blow, I'm incredibly conscious of that.
"But you can only take 31 players and that's the reality of it."
Schmidt - who will step down after the World Cup having guided the Irish to Six Nations titles and historic wins over world champions New Zealand, is likely to have the toughest decision in who to choose from backs Andrew Conway, Jordan Larmour, Chris Farrell and Will Addison who played well on Saturday.
"Will (Addison) did some things really well, he took a cut to the head and then got cramp, so we brought him off to protect him from injury," said Schmidt.
"He has such a balanced running style, he gets a good look at the pitch running back from fullback, and he's accomplished at kicking and kicking goals as well. So he's a good back-up from that perspective.
"He's underdone, he hasn't had as much rugby as we would have liked, but then versatility is a huge strength for him.
"So we'll be looking at him and comparing a few other guys, and seeing who best fits the mould."
Jack Carty looks set to be the third choice flyhalf - behind world player of the year Johnny Sexton and Joey Carbery who is recovering from an ankle injury - after a man of the match performance in the Welsh capital.
"Jack's done well, but it's apples, oranges and lemons," said Schmidt.
"You've got a number of different 10 options.
"One of them (Sexton) hasn't played yet, but we all know he'll play next week and will go.
"And another (Carbery) played very well for 50 minutes against Italy, and might be on the bench next week but will certainly be back in time for Scotland."