Pro 12: Blues v Ospreys (Fri) Adam Jones returns to the Ospreys side against the Blues on Friday night for the first since injuring a calf against South Africa in November. Jones is joined by skipper Alun Wyn Jones who rested for the region's 21-12 Heineken Cup win over Castres. Andries Pretorius returns to the Blues starting line-up after missing the Heineken Cup win over Glasgow. Pretorius is one of four changes form with Dafydd Hewitt, Rhys Patchell and Macauley Cook all coming back in. On the derby Blues director of rugby Phil Davies said: "We face an Ospreys side that is packed full of international talent and who have impressed this season to currently lie in fifth place in the table, just two points off a play-off berth. They also secured a big European scalp last week against Castres so will arrive full of confidence. We need to be ready to meet that challenge. "We are looking to build and improve on the form that has seen us secure some important results over the last two months," he added. We are under no illusions as to the size of the task that awaits us, but it's an exciting way to finish 2013 at the Arms Park. Despite the return of Adam Jones and Alun Wyn Jones the Ospreys will be without Richard Hibbard (broken hand) and Ian Evans, but the region will include Hanno Dirksen on the wing and Sam Davies keeps his place at full-back. Head coach Steve Tandy said: "This is the first game of a busy five weeks with three big derbies followed by the final two rounds of the Heineken Cup. We are looking to build some momentum after showing some good signs in the games against Castres, where we started to see the boys taking what we've been doing in training onto the pitch. It's important that we are at our best in Cardiff in front of a big and passionate crowd. If we can keep the momentum going and put in the kind of performance they expect, we'll be in a good place before back to back games against the Scarlets.  Blues' only defeat in their last five games in all tournaments was the 31-10 reversal at home to Munster in the Pro12 on 23 November. Blues have not beaten a fellow Welsh region, except by the dragons, since Ospreys visited the Cardiff City Stadium on New Year's Eve 2010. Ospreys have won just two of their last five Pro12 encounters - at home to both Dragons and Zebre anf have lost their last four away games in all competitions. Ospreys have won their last nine Pro12 fixtures against fellow Welsh regions since losing 21-20 to the Dragons at Rodney Parade on 6 January 2012. Blues: Leigh Halfpenny; Alex Cuthbert, Richard Smith, Dafydd Hewitt, Harry Robinson; Gareth Davies, Lloyd Williams; Sam Hobbs (capt), Kristian Dacey, Benoit Bourrust, Macauley Cook, Filo Paulo, Andries Pretorius, Robin Copeland, Rory Watts-Jones,. Replacements: Rhys Williams, Thomas Davies, Scott Andrews, James Down, Josh Navidi, Lewis Jones, Gavin Evans, Chris Czekaj. Ospreys: Sam Davies; Hanno Dirksen, Tom Isaacs, Ben John, Aisea Natoga; Dan Biggar, Tom Habberfield; Ryan Bevington, Scott Baldwin, Adam Jones, Alun Wyn Jones (capt), James King, Sam Lewis, Joe Bearman, Justin Tipuric. Replacements: Matthew Dwyer, Marc Thomas, Dan Suter, Morgan Allen, Tyler Ardron, Tito Tebaldi, Ashley Beck, Jeff Hassler. Referee: Jerome Garces (France) Assistant Referees: Rhys Thomas, Sean Brickell (both WRU) Citing Commissioner: John Charles (WRU) TMO: Gareth Simmonds (WRU)