It was confirmed yesterday that the USA international winger damaged ligaments in an accidental collision with Stuttgart goalkeeper Raphael Schafer during his team's 3-2 loss this week. He has returned to the USA to undergo surgery and Rangers manager Walter Smith fears he may not be able to call on the 25-year-old's services again in the current campaign.

"It's not a cruciate injury, he doesn't have to have reconstructive surgery done or anything like that," said Smith. "But it's a couple of ligaments at the side of the knee which need to be operated on.

"You are looking at a three to four-month recovery period after the operation and the awkward part is he would be coming back towards the end of the season. Sometimes you have to balance whether it's worth it or not.

"The worst case scenario is that we can discount him for the rest of the season."