The London Welsh centre Gavin Henson is expected to be sidelined for six weeks after fracturing his cheekbone during Saturday's pre-season friendly defeat against Llanelli Scarlets.
The 30-year-old former Wales centre played on until the 33rd minute after being tackled by Deacon Manu in the first minute of the 23-17 defeat, but was then taken to hospital for X-rays.
He had further tests yesterday and has now been ruled out for the start of the Premiership season, with Welsh facing Leicester on Sunday.
The head coach, Lyn Jones, tried to remain positive yesterday about the prognosis of the high-profile new signing.
"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 told the club's 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."
The Exiles last month handed Henson yet another chance to resurrect his career. He had been without a club since April, after being sacked by Cardiff Blues over his drunken behaviour on a flight returning from a game in Glasgow.
Henson previously worked with Jones during his time at the Ospreys, producing arguably the best rugby of his career and helping the region win two Celtic League titles and an Anglo-Welsh Cup.
Given the player's history the move will be considered by many to be a risky one for London Welsh as they prepare to embark on their first top-flight campaign.
Despite playing an integral part in Wales' 2005 and 2008 Grand Slam campaigns, and touring New Zealand with the British and Irish Lions in 2005, Henson has yet to deliver consistently on the glimpses of class he has shown during a checkered career.
The Blues were Henson's fourth club in little over a year after being released by the Ospreys in 2010 and having short stints at Saracens and Toulon.