Stoke manager Mark Hughes has voiced his anger at the tackle that left winger Brek Shea with suspected knee ligament damage in the American tour match against the Philadelphia Union on Tuesday night.
Former FC Dallas player Shea, who scored the only goal as a substitute in United States’ victory over Panama in the Gold Cup final on Sunday, scored one goal and made the other for Michael Kightly as the Potters won 2-0.
But a poor challenge from behind by Matt Kassel left him facing a spell on the sidelines and Hughes told Stoke's official website: "It's incredibly frustrating and hugely disappointing to lose Brek, especially in a game like this where you would expect players to look after their fellow professionals.
"I really have no idea what the lad was thinking about by going in for the challenge like that. Maybe he was trying to make a name for himself. Whatever he was thinking, it was totally wrong.
"We have been waiting a while to get Brek back here and, until the injury, he looked very bright, very dangerous and appeared to have a real understanding of what his role was on the left-hand side of midfield."
Hughes said the player would now be sent for a scan, and added: "We know we will definitely be without him for a number of weeks. It looks fairly serious, but fingers crossed it isn't any more serious than we already know it is."
Stoke won two and drew one of their three tour games, and return to the UK to visit Wrexham on Sunday and play Genoa at the Britannia Stadium the following Saturday.
"We are progressing, and that is a positive thing for us," Hughes said. "In the first half here [against Philadelphia], we looked very well organised, kept the ball incredibly well and managed to create a lot of opportunities."