Wigan Warriors head coach Shaun Wane criticised his side after they let a 14-point lead slip in Sunday's Super League loss at Hull KR.
In their first match since their World Club Series defeat by Brisbane, Wigan were leading 20-6 in the second half.
But Rovers scored three unanswered tries to seal their comeback win.
Asked if the Brisbane game affected performance, Wane said: "It probably did. It's a tough game, we played for 90 minutes but that's the way it is."
He told BBC Radio Manchester: "We chose to do it. I still think we could have come here and won the game quite comfortably.
"We were just dumb with the ball and just not acceptable."
Joe Burgess, Lee Mossop, Josh Charnley and George Williams all crossed to give Wigan a comfortable advantage, but four tries from the hosts, plus Josh Mantellato kicking one more goal than Matty Smith, gave them their first two points of the season.
"When we did get the ball, we scored, so it's a hard one to take," added Wane.
"I'm frustrated but the players understand that it is really simple - if we keep hold of the ball, we'll win games and that is what we need to do quickly."