Cardiff include Tim Mosey from Brisbane at full-back in Saturday's home fixture against Ebbw Vale at the Arms Park.
The young Australian was formerly with Mounts Bay in Cornwall and has been added to the Blue & Blacks Premiership squad for the rest of the season.
Team administrator Keith Morgan said, "We have received good reports on Tim and Lee Jarvis saw him play at first hand when he coached him at Mounts Bay. He looks to be a very useful addition to our options behind the scrum and with Roger Davies unwell earlier this week this seemed the ideal opportunity to blood him in a home fixture."
After ringing the changes in recent weeks, the coaching staff have opted for a more settled selection against the Steelmen with only three changes in the starting line-up.
Apart from the inclusion of Mosey the only other change behind the scrum is the return of Nathan Rees in place of Chris Czekaj on the wing. In the pack John Yapp comes in at tight-head prop for Kristian Gay.
Saturday's match has an early afternoon kick-off at 1.30 pm.
Meanwhile Cardiff's away fixture at Aberavon next month has been brought forward to Friday 21 November (kick-off 7.15pm).
Team: Tim Mosey; Ryan Howells, Shaun James, Luke Ford, Nathan Rees; Gareth Davies, Owen Ruttley (captain); Scott Roberts, Kieran Crawford, John Yapp, Matthew Veater, James Down, Damian Welch, Craig Everett, Rhys Shellard.
Replacements: Garry Horrigan, Kristian Gay, Adam Powell, Nick Hampson, Garyn Lucas, Lee Jarvis, Craig Morgan
All roads lead to Cardiff on Sunday for the SSE SWALEC Finals Day at the Millennium Stadium. Cambrian Welfare tackle Ystradgynlais in the Bowl final, Ystrad Rhondda play Newcastle Emlyn in the Plate final while defending champions Pontypridd face Bridgend in the Cup final.
WRU Chief Executive Roger Lewis, Deputy Minister for Culture, Sport and Tourism Ken Skates and WRU Chairman Gareth Davies earlier this week launched a new competition in conjunction with the WRU unveiling its archive room.
Welsh players and management joined Deputy Minister for Sport Ken Skates at the Pierhead Building, Cardiff Bay earlier this week to reveal the Union's pioneering school-club hub initiative has been so successful the project will now almost double the scale of the original project.
The Scarlets, Newport Gwent Dragons, Cardiff Blues and the Ospreys look ahead to Judgement Day III which sees the Blues take on the Ospreys (2.30) and the Dragons tackle the Scarlets (4.45pm) at the Millennium Stadium tomorrow afternoon.
Ystradgynlais and Ynysddu played out a titanic struggle at Taffs Well in the SSE SWALEC Bowl semi-final. At the end of the game neither team could be separated after a 15-15 stalemate but Ystradgynlais go through on try count.
Blues strike first in JD III battle - Newport Gwent Dragons lock Andrew Coombs, WRU referee Dylan Llyr Jones and Cardiff Blues hooker Matthew Rees decide dressing room allocations for Judgement Day III
Wales Under 18 captain Calum Haggett has received a conditional offer to read Biomedical Science at St Anne's College, Oxford. WRU chairman Gareth Davies went to meet Calum and Coleg y Cymoedd Principal Judith Evans to wish him luck in his exams and pass on some of his personal experience.