Cape Town - Western Province received a massive blow with the news that flanker Siya Kolisi will be sidelined for the rest of the Currie Cup season.Kolisi needs to undergo surgery after he broke his thumb in his left hand during WP's 26-23 loss to the Golden Lions in Johannesburg on Saturday. "Siya's injury is the only fresh concern from the weekend and it's obviously a very big loss for us at this stage of the season," commented WP coach Allister Coetzee.Coetzee is also left frustrated after WP lost another game which he feels they dominated."It's frustrating to play so well and to lose again - similar, in many ways, to the Sharks match (which they lost 23-25) at the start of the season."We went into an early lead but our discipline and individual errors cost us. We did well to come back and we could've won... then we could've drawn and then we ended up losing, so, clearly, the luck is not on our side at the moment! But we will keep knocking and learn from our errors - we remain as determined as ever to bounce back from these setbacks."We're back at home this coming weekend (against the Blue Bulls) and we have seven games left this season, so we have a chance to put things right and stay in touch for a semi-final place."WP's clash against the Blue Bulls at Newlands kicks off at 19:10 on Saturday.