Retiring Argentine flanker Juan Martin Fernandez Lobbe will captain the Barbarians against England on Sunday at Twickenham, live on Sky Sports Action, it has been confirmed.
The news comes after Ireland centre Bundee Aki had been originally named as Barbarians skipper for their current camp, but had to withdraw after sustaining an ankle injury in Connacht training.
Toulon flanker Fernandez Lobbe, who earned 71 caps for the Pumas between 2004 and 2015 and finished his Test career as captain of his country, will retire from the sport after Sunday's fixture.
The 36-year-old played in the Premiership with Sale Sharks between 2006 and 2009 before joining Toulon, where he was instrumental in their 201 Top 14 success and European Cup triumphs in 2013, 2014 and 2015.
Fernandez Lobbe also featured in three Rugby World Cups during 2007, 2011 and 2015.
"It's a real honour to lead the Barbarians," Fernandez Lobbe said in a released Barbarians statement.
"Since I was a kid I've been watching them play, and to me they represent the purest values of rugby.
"Playing England is a massive challenge as they are a top nation, but we have the sort of players here who love that kind of challenge.
"It's my last game ever, but I'm OK and at peace.
"I've been thinking about it for a long time, and this last year I've enjoyed every minute."
Current Bristol and former Connacht and Blues head coach Pat Lam takes charge of the Barbarians for their clash with Eddie Jones' charges.
The Barbarians' ranks include ex-England man Chris Ashton, All Blacks Malakai Fekitoa, Victor Vito, Luke McAlister and John Afoa, Wales flanker Justin Tipuric and Scotland half-backs Finn Russell and Greig Laidlaw
The Baa-Baas XV to face England was due to be announced at 2pm on Thursday, but was later pushed back to Friday.
England's team will be confirmed at 10am on Friday.
Barbarians:
Backs: Niyi Adeolokun (Connacht & Ireland), Chris Ashton (Toulon & England), Malakai Fekitoa (Toulon & New Zealand), Greig Laidlaw (Clermont & Scotland), Luke McAlister (Toulon & New Zealand), Josh Matavesi (Newcastle Falcons & Fiji), Semi Radradra (Toulon), Finn Russell (Glasgow Warriors & Scotland), Josua Tuisova (Toulon & Fiji), Rhodri Williams (Bristol & Wales).
Forwards: John Afoa (Gloucester & New Zealand), Denis Buckley (Connacht), Ultan Dillane (Connacht & Ireland), Juan Martin Fernandez Lobbe (C, Toulon & Argentina), Ramiro Herrera (Stade Francais & Argentina), Benjamin Kayser (Clermont & France), Nili Latu (Newcastle Falcons & Tonga), Tatafu Polota-Nau (Leicester & Australia), Sateleki Timani (Clermont & Australia), Justin Tipuric (Ospreys & Wales), Loni Uhila (Clermont), Flip van der Merwe (Clermont & South Africa), Victor Vito (La Rochelle & New Zealand).