Mike Phillips handed Wales an injury scare during Ospreys 25-24 Heineken Cup victory over Clermont Auvergne at the Liberty Stadium.
The British & Irish Lions scrum-half limped off in the 33rd minute with an ankle injury as Wales coach Warren Gatland looked on less than three weeks before the opening autumn international against New Zealand on November 7.
Ospreys coach Sean Holley said it was too early to know the extent of the injury and was just relieved his side secured their first win in Pool Three after seeing a 22-3 lead wiped out.
"Clearly it was nerve wracking and we are just glad to get over the line," said Holley, whose side drew 32-32 with Leicester last weekend.
"We wanted to come out and play with intent and move Clermont around the field and we clearly achieved that in the first half.
"We knew at half-time that they would come back at us, and they did that, but we did extremely well and showed some resolve to get back in front at the end.
"I'm really proud of them because we were up against the most formidable side that has been down here in a couple of years in terms of depth of squad and size.
"Like last week we probably should have pushed on and got the bonus point but we will wake up tomorrow and realise we are in a good position in the group."
Clermont coach Vern Cotter believed his side's lack of ball put them on the back foot in the first half before their recovery after the break.
"I think we didn't get our hands on the ball enough in the first half," he said. "I thought the Ospreys started well and scored points and we couldn't produce and maintain pressure.
"We either lost it on the ground or in the kicking exchanges and the yellow card (for lock Thibault Privat) didn't help us.
"We didn't get our teeth into the first half but in the second half we got our hands on the ball more and were able to express ourselves more.
"I was very happy with the character we showed in the second half. We had a fourth try disallowed and a penalty hit a post so we were in with a good chance of winning it at the end."
England Under-18 head coach John Fletcher insists his young side will be better for the experience after beating Italy in the bronze final to round out their 2015 Rugby Europe U18 Championship campaign in style.