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The Leicester forward has withdrawn from his place on the bench for Wednesday's clash against Wellington, when he will be replaced by his England colleague Richard Hill.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)
Ben Morgan starts at number eight for England on Sunday afternoon as the Red Rose take on Wales at Twickenham (kick off 3pm). The Gloucester back-rower spoke with Gloucester Rugby TV at Pennyhill Park as he and his international colleagues prepared for the eagerly anticipated RBS Six Nations' clash.
Billy Twelvetrees spoke to Russ Hargreaves of Talking Rugby at England training ahead of Sunday's huge RBS Six Nations clash with Wales at Twickenham. The centre is relishing the challenge of fronting up against a smart and talented Welsh back line.
Tim Taylor spoke to Gloucester Rugby TV after the 31 year old fly half announced that he was retiring from professional rugby. The Derby-born pivot, is excited for what the future holds for his new business ventures despite his career being cut short by a knee injury.
Dan Robson spoke to Gloucester Rugby TV at Franklin's Gardens following the 39-13 loss to Saints. The scrum-half enjoyed his battle with Lee Dickson but was gutted at the result as the Cherry and Whites did not do themselves justice, falling off in the closing stages to the league leaders.
Speaking after the game at Franklin's Gardens, Director of Rugby Nigel Davies reflected on a disappointing final quarter which saw Northampton Saints ease their way to a comfortable 39-13 win on Saturday afternoon.
Gloucester Rugby TV caught up with Gareth Evans this week ahead of the trip to Northampton Saints in the Aviva Premiership. The back rower explained his pride in his performances this season but knows there is still a lot for him to learn.
Gloucester Rugby travel to take on the table topping Northampton Saints in the Aviva Premiership on Saturday. Director of Rugby Nigel Davies is well aware of the qualities of Jim Mallinder's side, but Gloucester are the only team to defeat the Saints in the league this season.
Gloucester number eight Ben Morgan is hoping to start against Wales a week on Sunday, a team containing a number of former club team mates. He told the RFU.com website that he's looking forward to the prospect.
The Gloucester Rugby trio of Jonny May, Ben Morgan and Billy Twelvetrees played the full 80 minutes, and contributed well to England's 29-18 victory over Wales at Twickenham on Sunday as the English clinched their first Triple Crown since 2003.
There will be a trio of Gloucester Rugby players in the England Rugby starting line up for Sunday's huge clash with Wales at Twickenham. Number eight Ben Morgan is named to start with Billy Twelvetrees and Jonny May continuing in the back line.