Wigan have signed Norwegian defender Erik Hagen on loan from Russian side Zenit St Petersburg for the rest of the season.The 32-year-old usually operates as a centre-back and Latics boss Steve Bruce is delighted to have brought him in. 'Erik is a player who lives to defend,' Bruce told the club's official website. 'He is an experienced international and is no stranger to the big occasion. He is aggressive, fantastic in the air and can read the game very well. 'He is a leader on the field and he will add tremendous competition at the back for us. I wouldn't have brought him here unless I thought he had the attributes to be a hit in the Premier League.' Meanwhile, Bruce has admitted he 'got it wrong' by choosing to experiment with a three-pronged attack. The Latics boss opted to play new signing Marlon King alongside Marcus Bent and Emile Heskey at Middlesbrough on Tuesday rather than choosing between his three frontline strikers. But Bruce accepts the decision backfired as his side struggled to get to grips with the new formation and fell behind in a disappointing first-half performance. Wigan improved after King was replaced at the start of the second half and they reverted to a two-man strike force, almost managing to claim an equaliser. Bruce will therefore continue with a two-man attack in Saturday's home clash against West Ham and insists he will not make the same mistake again. 'I have to be honest and say that I think I got it wrong,' he said. 'I don't think that was the time to start changing the shape and the balance of the team. 'I think we were far, far better when we went back to a traditional 4-4-2, which the players are used to, but that's what we learnt from the other night. 'Marlon was impressive but I think he tired, which is understandable because he hadn't trained for a couple of weeks with what happened at Fulham.' Bruce swooped for King as Fulham stalled over signing the former Watford striker amid concerns over his medical. King's arrival has increased competition for places and with Bruce confirming he favours a two-man partnership, the Jamaica international is set to fight it out with Bent and Heskey for a starting berth. Bruce felt it was vital to make a move before the transfer window closed to boost Wigan's battle to beat the drop having slipped into the relegation zone when Heskey was injured earlier in the season. 'I think Premier League players know that you have to have that (competition for places),' said Bruce. 'Probably the reason I'm here and Chris Hutchings isn't is because he lost Emile Heskey for two months. 'If something had happened to Emile or Benty and you're without them in the run-in then you are goosed. 'That's the stupidity of this transfer window that situations like that could arise.'