Melbourne Victory coach Ange Postecoglou has poached his first player from his former club, further reducing battling Brisbane Roar's defensive options.The Victory has swooped on Young Socceroo Jason Geria and signed him to a three-year deal at a time he was close to making an A-League debut for the Roar.Brisbane will be without first-choice defenders Matt Smith and Ivan Franjic against Newcastle Jets on Saturday night due to their Socceroos call-up for the East Asian Cup qualifying tournament.Youth squad member Geria, 19, had been vying with Japanese import Yuji Takahashi and James Donachie to partner Matt Jurman in central defence but was a notable absentee from Roar training on Thursday morning.On training formations, it appears Takahashi will again be overlooked with tall teenager Donachie, a contracted senior player, to start against the Emile Heskey-powered Jets at Suncorp Stadium.Heskey has scored five goals in eight games for fourth-placed Newcastle and the former England striker is sure to provide the inexperienced Roar defensive line with a major challenge."It's obviously a big loss, losing Ivan and Smithy at the back but we've got great players at this club who can come through and do the job," said right fullback Jack Hingert."Obviously Heskey has been banging a few goals in and he's a big presence up front there but we have a couple of boys at the back (Jurman and Donachie) who are big and strong and I'm sure they'll put in a good performance against him."Hingert, who started just two matches in the Roar's triumphant 2011-12 campaign, admitted he had to quickly emerge as a senior defender."I've got to step it up a bit more this week and have to age a couple of years in the next couple of days but I'm looking forward to it," he said.The 22-year-old has been one of the Roar's more impressive performers in their poor start to the season.Five losses in eight matches has left them second last on the ladder and caused some friction, with midfielder Erik Paartalu taking exception at coach Rado Vidosic's criticism of their 2-1 loss to Central Coast.Hingert denied the dressing room took offence at Vidosic's outburst and said they were all pulling in the same direction for Saturday night's "must-win" encounter."All the boys are really close to be honest," he said."We get on really well and we have a lot of belief in each other."We have no doubt we can turn it all around."