Gavin Henson will undergo further tests to confirm if he fractured a cheekbone in London Welsh's friendly defeat against Scarlets, the Aviva Premiership club has confirmed.
Henson was taken to hospital and given X-rays and tests after he was tackled by Deacon Manu in the first minute in the 23-17 loss, and although he played on until the 33rd, he had to be replaced and could now miss the start of the season with Welsh facing Leicester on September 2.
A club spokesman said: "Gavin underwent X-rays yesterday and will have further tests today and there has been no confirmation if his cheekbone has been fractured."
He added: "Until we know the extent of the damage we will not know if he will miss the game against Leicester and there is not much more we can say at this point."
London head coach Lyn Jones is trying to remain positive about the prognosis of the former Wales three-quarter.
"We're hoping for the best, but if it's the worst he's not the first player to get injured and we'll just have to be patient and deal with it," Jones said, in quotes carried on the club website.
"These are things you've got to deal with in rugby. You've got to deal with thunderbolts all the time.
"No player wants to get injured in a pre-season friendly because it's hugely frustrating because of all the hard work that's been done leading up to the start of the season."