Philadelphia Union manager Peter Nowak has backed goalkeeper Chris Seitz despite the fact he let in a soft goal on the weekend.

The Union dominated proceedings against the Kansas City Wizards at PPL Park but a 71st minute Davy Arnaud free-kick from a tight angle managed to evade Seitz and force the game to a 1-1 draw.

Nowak said the goal should not have occurred and said Seitz was not there for his teammates but maintained his faith in the gloveman.

"It is disappointing," Nowak said. "We still believe in [Seitz] and his ability to make crucial saves.

"It was an unnecessary goal and I think our defense made it easy for him. When it comes to the crucial moments, he has to be there for the team."

Seitz did accept blame for the goal, admitting that he was worried about the Wizards' aerial prowess.

"I think he was at a pretty tough angle and that team is very strong in the air and it was something I was focused on," Seitz said. "I was worried about crosses and I have to raise my hand and take the blame for that."