Wales will be without Joe Allen for the World Cup qualifier against Georgia in Cardiff on Sunday.
The 26-year-old Stoke midfielder suffered a hamstring injury in the early stages of the second half in Thursday's 2-2 draw with Austria in Vienna.
Allen had given Wales the lead with a stunning half-volley in the first half, his second goal in two Group D qualifying matches having also netted in the 4-0 victory over Moldova in September.
Allen's absence is a further blow for Wales boss Chris Coleman with fellow midfielder Aaron Ramsey still sidelined with a hamstring problem.
The extent of Allen's injury is unclear but he may miss Stoke's next Premier League match, at home to Sunderland, on October 15.
Coleman is hopeful that will not be the case though, and he expects Allen to be fit for the visit of Serbia in November.
"We've had a scan and something showed up, so you have to be very careful with it," said Coleman.
"If he has a good week he may play for Stoke next weekend, but this one is too soon for him.
"So from between now and then what he does is going to be very important. Let's make sure he's looked after properly and he's ready for the next one."
Allen, who joined Stoke from Liverpool in July for just over £13million, has scored in his last two matches for his new club against West Brom and Manchester United.