DC United's star signing Danny Szetela was left out of the club's Champions League loss to Marathon for reasons unknown.

United coach Tom Soehn said it was his choice to leave the former Racing Santander midfielder at home.

"It was a coach's choice," he said.

"We made him work hard while we were gone, so today he was a bit sore. We will see how he responds."

When quizzed on the reasons for his absence, Szetela was holding his cards close to his chest.

"A little bit (surprised). I talked to Coach about it. There were a few personal things that came up and it's important for me right now to get my fitness up and be ready for these games," he said.

"It's more just between the team. I'd rather keep it between the team."