Lions flanker Lewis Moody faces a race against time to be fit for first Test contention against New Zealand next week.
The Leicester forward has withdrawn from his place on the bench for Wednesday's clash against Wellington, when he will be replaced by his England colleague Richard Hill.
The Lions confirmed Moody had suffered an injury to his left knee in training, but the apparent seriousness was not revealed until coach Gareth Jenkins spoke to the media in Wellington on Tuesday.
Jenkins revealed that Moody is "out of the selection process" for next Saturday's game against Otago in Dunedin, and that will seriously hamper his Test prospects, given the Lions boss Sir Clive Woodward is likely to have finalised his first choice line-up by early next week.
Moody has not travelled to Wellington, remaining behind at the squad's Christchurch base for further tests.
Three players - Lawrence Dallaglio, Malcolm O'Kelly and Simon Taylor - have already been ruled out of the tour because of injuries.
The possible loss of Moody would be a huge blow, given his versatility at blindside and openside flanker, but it would appear the signs are not good.
Prop Andrew Sheridan, meanwhile, is battling to overcome an ankle injury sustained against the New Zealand Maori last Saturday, raising doubts about his prospects of being fit to face Otago. Like Moody, Sheridan is a serious candidate for the Lions' Test 22.
The British and Irish Lions team to play Wellington on Wednesday is:
J Lewsey (Wasps and England); J Robinson (Sale and England), B O'Driscoll (Leinster and Ireland, capt), G Henson (Ospreys and Wales), G Thomas (Toulouse and Wales); J Wilkinson (Newcastle and England), D Peel (Lanelli and Wales); G Jenkins (Cardiff and Wales), S Byrne (Leinster and Ireland), J White (Leicester and England), D Grewcock (Bath and England), B Kay (Leicester and England), S Easterby (Llanelli and Ireland), N Back (Leicester and England), M Corry (Leicester and England).
Replacements: G Bulloch (Leeds and Scotland), M Stevens (Bath and England), P O'Connell (Munster and Ireland), R Hill (Saracens and England), C Cusiter (Borders and Scotland), S Jones (Clermont Auvergne and Wales), S Horgan (Leinster and Ireland)
James Hook was delighted with the Cherry and Whites' overall performance on Saturday afternoon, but was quick to praise the effort in the first half in putting the game in their control, as Harlequins were dismissed 28-6 at Kingsholm.
Speaking immediately after the 28-6 victory over Harlequins on Saturday, Tom Savage praised his team mates for building on their fast start. The second row admitted there's still lots of work to do for Gloucester but that the side are heading in the right direction.
Speaking to GRTV after the game, Director of Rugby David Humphreys spoke of his delight in securing a 28-6 win over Harlequins at Kingsholm. He hailed the home side's defence which they were quick to turn into attack.
Speaking to the local media, Bill Meakes this week explained how he was relishing the challenge against Harlequins at Kingsholm, and that he is enjoying the opportunity to develop his game time, and repaying the faith from the Cherry and White coaches
Gloucester look to build upon the local derby win over Bath last weekend with Harlequins the visitors to Kingsholm on Saturday (kick off 3pm). Director of Rugby David Humphreys is expecting a close game with the two teams well matched, although it may not be a 78 point thriller like the last time the two teams met.
Named Man of the Match by BT Sport, scrum-half Willi Heinz said after the 15-11 win at Bath on Friday evening that it was a pretty happy Gloucester dressing room and reward for a lot of hard work put in during the week leading up to the game.
Speaking after the 15-11 win over Bath at the Rec on Friday evening, David Humphreys heaped praise on his players, pointing out how they had bounced back after last week's tough defeat to overcome a rough start before controlling the game and earning the win.
Gloucester Rugby hooker Richard Hibbard spoke to the local media this week as the Cherry and Whites prepare to face Bath Rugby in the Aviva Premiership. The Welshman is ready to bounce back at The Rec.
After a disappointing opening weekend loss to their Scottish counterparts, England U20s will be eager to bounce back in Italy this evening, with Gloucester flyer Mat Protheroe set to pull the strings from fly half.
Gloucester Rugby make just the one change to the starting line up that won at Bath last Friday evening, flanker Matt Kvesic restored to the starting XV as the Cherry and Whites welcome Harlequins to Kingsholm in the Aviva Premiership on Saturday (kick off 3pm).
The Early Bird deadline for ticket purchases for the Aviva Premiership fixture against Harlequins on Saturday will expire at 6:30pm on Thursday evening, with tickets already limited for one area of Kingsholm.