**The Welsh regions kick off the Guinness PRO14 Rainbow Cup with a trio of derby fixtures.** Round 1 will see the Ospreys host Cardiff Blues on Saturday before the Scarlets head to Newport to face the Dragons on Sunday. Here, we take a closer look at both matches. **OSPREYS vs CARDIFF BLUES** **The breakdown** The Ospreys rounded off their PRO14 campaign with a shock win at eventual champions Leinster.