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The Leicester forward has withdrawn from his place on the bench for Wednesday's clash against Wellington, when he will be replaced by his England colleague Richard Hill.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)
Jonny May's superb late score capped a thrilling 40-32 European play-off win over Connacht on Sunday. The winger spoke afterwards of his team's character and spirit as he looked ahead to one more week of rugby.
Speaking to GRTV this afternoon, Director of Rugby David Humphreys hailed the 'never say die' attitude of the team, after despite not being at their best, fighting back to take a 40-32 win after extra time over Connacht.
Jonny May continues on the wing on Sunday as Connacht come to town, and the England wing explains to the local media this week that he is delighted with his form and is looking forward to taking on Pat Lam's men.
Speaking to the local media this week, front rower John Afoa is familiar with the challenge of Connacht from his time in Belfast, and the World Cup winner is fully aware of the challenge they pose ahead of Sunday's meeting in the Champions Cup play off
Speaking ahead of Gloucester's European Rugby Champions play-off against Connacht on Sunday (Kingsholm, 3:30pm), Director of Rugby David Humphreys admitted that he's glad to have more players available than in recent weeks ahead of a tough fixture.
Nick Wood captained the Cherry and Whites on Saturday afternoon, and the experienced front rower expressed his pride in the young squad in defeat to Bath on the final day of the Aviva Premiership season.
Lewis Ludlow scored Gloucester's opening try in the 30-50 defeat at Bath on Saturday, part of an impressive performance by the young back row forward. Speaking after the game, he paid tribute to the young Gloucester side who went toe to toe with the Aviva Premiership semi-finalists.
Speaking to the local media after the game, Director of Rugby David Humphreys gave an honest assessment of the game, and expressed his pride in the way his young charges had performed against the title-chasing hosts.
Speaking to the local media this week, Gloucester Rugby scrum half Callum Braley is excited by the challenge of the West Country Derby, and the ex-Bristol man reveals the squad will be giving their all.
At the recent London Irish game, personnel from the Imjin Barracks in Innsworth, including Gurkhas, were present, holding a collection to raise funds for ShelterBox to aid relief from the recent Nepal Earthquake Appeal.
It was a thriller at Kingsholm on Sunday afternoon, as Gloucester snatched victory from the jaws of defeat, leveling the scores in the final minute before triumphing in extra time over a spirited Connacht side.