Cardiff Blues head coach Danny Wilson has billed his side’s local derby against Scarlets in the GUINNESS PRO12 on Saturday as the biggest game of the season. The Blues make the short trip west to Parc y Scarlets eight points behind Munster in fourth and seven behind Glasgow Warriors who sit sixth. Wilson said: "A top-six finish is a challenge for us to get, but with four games to go we have got something big to fight for which maybe in previous seasons hasn't always happened. "This game becomes the biggest of our season; to give ourselves the opportunity to carry on with that quest for the top six. "Every game is simply huge now and we have got to get a victory. We know to win away from home, at one of the toughest places to go in the Guinness PRO12 and get a result, it is going to need to be top drawer display from us.” Cardiff Blues welcome back record appearance holder Taufa'ao Filise to their starting line-up on Saturday in one of two changes. The Tongan prop has racked up 213 games for the Blues since joining the Welsh club from Bath in 2006. Also in the front row, hooker Matthew Rees returns to the team to face his former region while a positional change will see Sam Warburton and Ellis Jenkins switch flanks in the back row. Alex Cuthbert underwent knee surgery on Wednesday and will miss the rest of the season. Meanwhile, the Scarlets welcome back Welsh international Samson Lee to their starting line-up in the only change to the side that beat Ospreys 25-16 last weekend. Scarlets are third in the league and now a win will move them a massive step closer to securing a top-four finish as well as qualification for the European Champions Cup next week. Scarlets head coach Wayne Pivac said: "There will be a lot of intensity in terms of personal battles for Wales jerseys and some thrilling individual match-ups right across the park. “We know they're playing very well and scoring a lot of tries. They're trying to get up the table to qualify for Europe. "From a team point of view it's definitely one game at a time for us. We're in a position where we can control our destiny." At Parc y Scarlets, 3pm. Live on Sky Sports and S4C Referee: Marius Mitrea (FIR, 50th competition game) Assistant Referees: Wayne Davies, Greg Morgan (both WRU) Citing Commissioner: Aurwel Morgan (WRU) TMO: Jon Mason (WRU)