Everton have been left sweating over an injury concern for Nathan Patterson.
Patterson was stretchered off during Scotland's Nations League win against Ukraine.
The 20 year-old defender could now be set for a lengthy spell on the side-line after Scotland boss Steve Clarke admitted that the injury "doesn't look too good".
After challenging for a header, the defender landed awkwardly and seemed to pick up a knee injury.
He was able to walk himself off the pitch but looked in some discomfort before being stretchered down the tunnel.
"Nathan Patterson, it doesn't look too good, obviously felt something on his leg," Clarke told Premier Sports.
"We'll just have to wait and see how it pans out. Hopefully it's not too serious, and hopefully he's not out for too long."