Arsenal winger Christos Tzolis was substituted with an apparent injury in the 18th minute of Greece's 2-2 Nations League draw against the Netherlands on Thursday.
The 24-year-old went to ground and was then replaced by Georgios Masouras, pulling his shirt over his head and looking visibly upset as he made his way to the sidelines.
Greece had raced out to a 2-0 lead over the Netherlands with Fotis Ioannidis scoring a goal and setting up another before Virgil van Dijk cut the lead in half with a header.
Denzel Dumfiries had a goal ruled out for offiside when the Dutch looked to have drawn level, but Tijjani Reijnders scored in the 89th minute to earn Netherlands a point in the Group A2 match in Thessaloniki.
"The Dutch changed tactics in the second half and we didn't respond adequately," Ioannidis said. "But I believe we definitely have moved up a level and are getting better by the day."
The Netherlands, who are playing their first games under new manager Xavi Hernandez, also needed a late equalizer against Germany.
"I wish I had an answer for that right now, but indeed, it's unacceptable," the Liverpool star said of his team's results during the international window. "When we tried to play through the middle, we lost possession far too quickly. It just wasn't good enough in the first half."
Greece, meanwhile, pulled off a stunning 1-0 upset of Germany in Augsburg in their last game and will face Jurgen Klopp's side again on Sunday in a rematch to close the September/October international window.
Tzolis' availability for that game is unknown after his early withdrawal on Thursday. He has made five appearances for Arsenal this season since joining from Club Brugge in the summer window.
Greece remain as the surprise leaders of the group, having also beaten Serbia prior to the win over Germany.
"We are unbeaten and we are top of the group, so we have to build on that," Greece defender Kostas Tsimikas said. "There is a sense of disappointment, but we must be humble and recognize that we played against a superpower.
"In the end, that point we earned may prove to be very valuable."
Information from The Associated Press and PA was used in this report.