Adelaide United coach Aurelio Vidmar is keen for his players to tighten up and stop allowing easy goals in. The Reds have kicked off the A-League season in less than impressive fashion, winning just one game out of four, and Vidmar believes it is due to being mentally fragile.

"I said that in terms of the way we were giving away our goals," he said.

"It tells you that people are not thinking. We have gone through the DVDs with the defenders, but it is not just about them.

"It's what the guys up front are doing and there were times with the midfielders not tracking their man. They are real simple things that can be fixed.

"They are aware of it, the next step is to execute it and if someone runs past actually go with your runner.

"They are small things, but at this point in time we are copping it."

Adelaide are away to seventh-placed Wellington Phoenix this Friday September 4, with kick-off at 7:30pm local (5:30pm AEST).