England head coach Stuart Lancaster was handed a further blow ahead of their tour to New Zealand with Mike Brown hobbling off during Harlequins' Premiership semi-final.
The England flyer, who was crowned Premiership Player of the Season on Thursday, required medical attention in the closing stages of Harlequins' 31-17 defeat at the hands of Saracens on Saturday.
The potential loss of Brown - this season's RBS Six Nations Player of the Championship - is a possible hammer-blow for England, and Quins shared his pain as their season reached its conclusion.
It presented a major scare for England coach Lancaster, who will have a depleted side to face the Barbarians on June 1, before flying to Auckland for a three-match Test series against the All Blacks starting on June 7.
"Hopefully, it is just a little twinge," Harlequins director of rugby Conor O'Shea said.
"It was hot out there, and the surface is different to what we are used to playing on.
"It's a twinge, I hope, nothing more, but we will see after the next couple of days. He has got a few weeks until that first Test in New Zealand. Hopefully, he is alright."
Due to the Premiership final taking place at Twickenham on May 31, Lancaster will already be without Saracens and Northampton Saints representatives for the opening Test against New Zealand.
That means forwards Mako and Billy Vunipola, Dylan Hartley, Alex Corbisiero, Courtney Lawes and Tom Wood will all miss the first match, as will Owen Farrell, Brad Barritt, Chris Ashton, Alex Goode, Lee Dickson and Luther Burrell of the backs department.
Although Lancaster does now have the luxury adding Harlequins and Leicester Tigers players to his initial training squad, the England coach will wait with trepidation over the fitness of Brown.