Leinster coach Sean O'Brien will line out for Naas RFC in the Energia All-Ireland League this season.The province's contact skills coach will join the Division 1B side, having had a request to play for his home club Tullow turned down by the Leinster branch.O'Brien, who retired from playing professionally last summer, was denied permission to feature for the Leinster League side, with the branch's welfare regulations stating players must be at least two seasons removed from professional rugby before they can play at the junior grade."All players who have played international (including Sevens), provincial, or professional rugby in any jurisdiction for the senior full team, in the current or last two preceding seasons, shall be ineligible to participate in any competition," states regulation 5.7.With no such eligibility issues in the AIL, O'Brien is free to play with Naas, and the Kildare club have confirmed to RTÉ Sport that the Leinster coach will join them for the coming campaign.Naas, coached by former Munster and Leicester Tigers wing Johne Murphy, were beaten by Shannon in the Division 1B final last season, narrowly missing out on promotion to the top tier.Their new season started with a heavy 37-7 defeat to Old Wesley on Saturday.A 56-cap Ireland international, and two-time British and Irish Lion, O'Brien's signing is a major coup for Naas, although it remains to be seen how often he will be able to feature for the club, given his commitments with Leinster.