But Roberts, who scored a try in the decisive third and final Test against Australia last summer to help seal a 2-1 series win, says he has faith in Gatland to reproduce his winning formula.
"We have a very experienced coaching team who have been around a long time," he said.
"People will say our game-plan is quite predictable, but it definitely isn't.
"We like to stay unpredictable on the field, but we've taken the wrong options on the weekend at times. It's tough, but we stick with it.
"We have to put trust in the coaches, put trust in what we are trying to do on the field and ultimately execute better as a team."