Easterby was hugely disappointed with the Scarlets defeat
Simon Easterby admits the Scarlets must wise up to avoid falling to another "embarrassing" defeat.
The west Wales region kicked off their RaboDirect Pro12 season with a 42-19 defeat to reigning champions Leinster.
Easterby's men appeared on course for an impressive victory at Parc y Scarlets after leading by six-points at the interval.
But Leinster ran riot in the second-half with three tries coming in the space of just 13 minutes.
"We felt we produced some really good rugby in the first half and were in control, but we conceded an early try in that second half, lost our composure and never got control back.
"Our scrum was good, we had good possession and field position and the scoreboard was ticking over.
"We did everything we talked about ahead of the game but after half-time we had a bit of meltdown. We started chasing things, the more we chased things the more we tried to force things and the ball was more often than not lost.
"We can't fault what we were doing up until half time. But some individual error, composure lost and maybe our leadership was lacking.
"We have to improve our game management, we have to make sure we don't embarrass ourselves again.
"Mistakes are frustrating and if you make that many it is very difficult to win a game of rugby. When you have a team that capitalise on mistakes like Leinster, you are going to put yourself under pressure."
The Scarlets woes were compounded by an injury to Joe Snyman. The South African second-row left the field with his arm in a makeshift sling and he will be assessed today.
"We're not sure on the extent of Joe's injury yet. We picked up a couple of bumps but hopefully nothing too serious."
As the countdown continues for RWC2015, Tournament Chief Executive Debbie Jevans visited the Millennium Stadium to discuss preparations for the eight matches and reveal the positive news that 100,000 tickets for games at the home of Welsh rugby have sold in the last seven days.
Jason Harries is targeting a first win on the World Series circuit this season with Wales. The series returns to action this weekend in Dubai where Harries is part of a team hoping to build from its efforts in round one in October.
Wales skipper Jevon Groves says his side have addressed a few points from Gold Coast and aim to 'hit the ground running' in the next two rounds of the World Series, kicking off with this weekend in Dubai before heading off to South Africa next week.
Wales Sevens manager Steff Thomas is hopeful his side can build from a quarter-final spot in the opening round of the World Series in Australia when his side take part in the forthcoming double header in Dubai and South Africa.