British and Irish Lions prop Cian Healy's tour was brought to a premature end after a scan on his ankle revealed ligament damage.
Just hours after he was cleared by a disciplinary hearing, the Irishman received the dreaded news regarding the injury he sustained in the Lions' win over the Western Force on Wednesday.
The recovery time is expected to exceed the duration of the tour.
And in another injury setback, Mako Vunipola will start for the Lions against Reds on Saturday after Gethin Jenkins suffered tightness in his calf during today's captain's run.
The Saracens prop takes over at loose-head, while Leicester Tigers' Dan Cole comes on to the replacements' bench.
Meanwhile, prop Ryan Grant has been called up from Scotland's tour of South Africa.
Grant will fly from Durban this evening and arrive in Brisbane tomorrow following the injuries to Jenkins and Cian Healy.
Lions coach Warren Gatland admitted that Healy's injury was a big blow to his side.
"Firstly, our thoughts are with Cian," he said.
"It has been a day of mixed emotions for him after being quite rightly being cleared of foul play but then the scan revealing the extent of the damage to his ankle.
"He has made a big contribution on and off the field in the last two weeks and we wish him well in his recovery.
"Gethin has trained all week but he felt some tightness in his calf today so it's right not to play him.
"We will assess him over the next 24-48 hours but Mako has done well in the last two games and this is another chance for him to step up.
"Given Cian's injury we have decided to bring Ryan in. He has played well in the PRO 12 this season and for Scotland in the Six Nations and we look forward to him and Alex Corbisiero arriving tomorrow."
Lions (revised): 15 Stuart Hogg, 14 Alex Cuthbert, 13 Manu Tuilagi, 12 Jonathan Davies, 11 Tommy Bowe, 10 Owen Farrell, 9 Ben Youngs, 8 Toby Faletau, 7 Sam Warburton (capt), 6 Dan Lydiate, 5 Geoff Parling, 4 Richie Gray, 3 Matt Stevens, 2 Tom Youngs, 1 Mako Vunipola.
Replacements: 16 Richard Hibbard, 17 Dan Cole, 18 Alun-Wyn Jones, 19 Paul O'Connell, 20 Justin Tipuric, 21 Conor Murray, 22 Jonathan Sexton, 23 George North.