Jamie Robinson will lead the Blues when they play The Borders in the Celtic League match at the Arms Park on Friday evening (7.15pm).
It will be the first time for the young international centre to lead either the Cardiff club or Blues' regional sides but coach David Young has had no hesitation in appointing him.
Young said, "Jamie is still only 23 but he is already in his fifth full season of senior rugby and has grown in stature from year-to-year. He has the respect of all his team-mates and giving him this honour for this game has already proved very popular with them."
Robinson made his first team debut for Cardiff on 7 April 1999 - his 19th birthday - and this weekend's game will be his 124th in the colours of Cardiff and the Blues. So far he has scored 37 tries for the two sides.
He leads a much changed Blues side with six new faces from last week when the Blues recorded their fourth consecutive victory when winning in Connacht. Jonny Vaughton and Tom Shanklin return on the wings and Pieter Muller partners Robinson in the centre.
Andrew Moore starts at scrum-half and in the pack the changes see Darren Crompton and Jim Brownrigg come into the side. A further positional change sees Craig Morgan move to full back.
Team: Craig Morgan; Tom Shanklin, Jamie Robinson (captain), Pieter Muller, Jonny Vaughton; Nick Robinson, Andrew Moore; Darren Crompton, Rhys Thomas, Ben Evans, Heino Senekal, Jim Brownrigg, Matt Cockbain, Nathan Thomas, Robin Sowden-Taylor
Replacements: Ken Fourie, Andrew Lewis, Craig Quinnell, Andy Moore, Ryan Powell, Nick Macleod, Nick Walne
Referee: Marshall Kilgore (Ireland)