Preston midfielder Ross Wallace believes signing a permanent contract at Deepdale will boost his chances of a call-up to the Scotland squad.The 23-year-old, who completed his move from Sunderland this month, has so far been overlooked by Scotland boss George Burley and predecessor Alex McLeish."Missing out on the last two squads has been disappointing," Wallace told BBC Radio Lancashire."Hopefully when the next one comes around I'll have had a few more games."The Dundee-born player initially joined North End on loan from Sunderland in August.But having impressed in recent games, manager Alan Irvine made Wallace his second signing of the January transfer window, the player signing a four-and-a-half year contract.And Wallace believes he can help Preston finally reach the Premier League."I intend to play at the highest level I can possibly play at," he said."We've got a good bunch of players here and if the manager can add one or two more then we've got a half-decent chance."