"It came down to the fact that his P1 Visa was denied," Wilkinson told oregonlive.com. "He will not be joining us this year.
"It was taking too long. We always had a deadline on it and that deadline was extended a little bit.
"Going into the first game of the season, I think it was important that the fans, the players and the coaching staff to know what we've got and what areas we need (to address) without continuing down a path where we don't know what the outcome will be."