Roberto Martinez has said new goalkeeper Vladimir Stojkovic from Sporting Lisbon will bring "character" and "determination" to his Wigan squad. The 26-year-old has joined Latics until the end of the season and will go straight into the squad for the Premier League game against top-four hopefuls Aston Villa on Saturday. The Serbia international says he is excited at the prospect of playing in England and providing competition for number one Chris Kirkland. "Everyone knows about the quality of the English Premier League," said Stojkovic. "So to get a chance like this is a fantastic opportunity for me." He added: "It is going to be very tough because I know the quality of the goalkeepers already here but every professional trains to play first-team football. "I am looking forward to the challenge of getting in the team and fighting for a place." DW Stadium boss Martinez added: "He will add tremendous competition for places in the goalkeeping department - something which we need everywhere on the pitch."