Leave me in Origin back-row, says Gallen Willie Mason will get a chance to leave a serious impression on NSW State of Origin skipper Paul Gallen on Sunday. The two will butt heads as Newcastle host under-pressure Cronulla in a match where Mason's Origin credentials will go on the line. Mason, who last played for the Blues in 2008, is pushing hard for a recall and received a boost to his playing stocks with Gallen insisting he be played in the back-row. The Cronulla captain, who is desperate to halt a four-game losing streak when the Sharks travel to Newcastle on Sunday, has dominated at Origin level in the front-row but reiterated his desire to wear No.13. That frees up a starting spot alongside Test prop James Tamou - a role which many feel is the perfect fit for Mason to make his return to the game's biggest stage. I prefer playing back-row. At the end of the day, I'm 105 kilos compared to these blokes who are 115," Gallen said. It is a lot easier for me playing in the back-row playing behind some of these bigger guys. Mason is duelling with the likes of Tim Grant, Trent Merrin, Tim Mannah, Aaron Woods, Aiden Tolman and another opponent on Sunday, Cronulla's Andrew Fifita, for a Blues jersey. Gallen says the opportunity is there for someone to barge their way into the side. "I think blokes have got to be playing good for a long time to get their spot in this side," he said. Jimmy Tamou will be one front-rower and it's up to those guys as well as the Tolmans of the world and Woods to try and get that other spot. (Mason) has been playing well. Hopefully he has a quiet week this week because I'm playing him. The Sharks slipped to 13th on the ladder following last week's sloppy loss to Canterbury, and Gallen admits a similar effort against Newcastle will end in disaster. "I was disappointed we didn't capitalise on our opportunities (against the Bulldogs) but certainly, against a good side like Newcastle, we've got to capitalise on any opportunity that we get and limit the opportunities they get," he said.