Craig Morgan is a slight doubt for Wales ahead of their Euro 2012 qualification opener against Montenegro.
The 25-year-old, who joined Preston from Peterborough over the summer, took a knock to his foot in training on Wednesday.
National coach John Toshack is now sweating on the defender's fitness, but hopes he will be still be in contention for Friday's crunch clash.
"He is the only doubt at the moment," said Toshack.
"I think he'll be OK. He went for an X-ray yesterday morning and it didn't show anything important.
"Hopefully he will be able to train today. He was able to do some running yesterday - no contact with the ball at all - but hopefully he will come through OK."
Wales, who have not featured at a major tournament since 1958, are looking forward to getting their campaign up and running, but Toshack admits there are a few nerves knocking around.
He said: "I think they are a little bit tense.
"At the same time they want to do well, they realise the importance of getting off to a good start.
"When you look at the teams in the group, it is a very open group. England would be the favourites but there is not a great deal to choose between the rest of us.
"I sense they are very keen to do well, if a little bit apprehensive. That is not necessarily a bad thing and we are just waiting for it to kick off now."
Meanwhile, Bristol City defender Christian Ribeiro has withdrawn from the Wales U21 squad ahead of games against Hungary and Italy.
The 20-year-old, who missed the majority of last season after damaging cruciate knee ligaments, feels he is still some way short of the levels required to compete internationally.
"I have only played in two reserve games. I had 45 minutes against Cheltenham and 90 minutes against Aldershot," said Ribeiro.
"My fitness levels got so low and I have had to work really hard to get them back up.
"Hopefully, soon I will get a chance to show what I can do and reap the rewards."