Marlon King is adamant he is fit to fight for the Wigan cause this season after the club took advantage of his collapsed transfer to Fulham.The striker has signed a three-and-a-half-year contract with the Latics, who have structured a financial package with Watford that will see them pay no more than £4million in total. Fulham attempted to conclude a deal last week for the 27-year-old, who scored 37 goals in 87 appearances for the Hornets, but are understood to have been unhappy with a technicality in King's medical, which led to them trying to renegotiate the transfer. Wigan then stole a march on their rivals, with King passing a medical with flying colours. The striker is ineligible for today's FA Cup fourth round tie with Chelsea at the JJB Stadium but he should make his debut in the Premier League clash at Middlesbrough on Tuesday. 'I was down at Fulham and had a long medical. For some reason it hit a hitch, and I think the two clubs were trying to renegotiate the fees, which had nothing to do with me,' said King. 'I then picked up the papers to see I had failed a medical, but I know my body is 110%. I would like to say I didn't fail a medical. I have been playing for a season and a half now and scoring goals. 'So as far as I'm concerned and as far as Wigan are concerned, I'm fit and well. Steve Bruce made it clear he wanted me. He made me feel very welcome.' King joins two other English strikers in Emile Heskey and Marcus Bent at the JJB Stadium, with Bruce confident his new signing will play a full role in helping the club in their bid to stay in the top flight. 'He's a proven finisher who provides us with a different kind of goalscoring threat,' said Bruce. 'He has scored goals at every level he has played at and he is hungry to make an impact in the Premier League again. 'I believe he is the kind of player who could make a real difference to us.' The Latics, who share the ground with rugby league side Wigan Warriors, have been concerned about the state of the JJB pitch but will have to wait until the summer before possibly tearing it up. 'It's difficult because we've the rugby and the football, and it's always going to be a problem,' said Wigan assistant manager Eric Black. 'I understand the chairman has spoken to Steve and come the end of the season he will look to renew part of it, or at least do what he can to ensure it is in a good state. 'But that will be at the end of the season because there is not an awful lot we can do now because the rugby season starts soon.' It is a similar message from captain Mario Melchiot, who faces the club with whom he won the FA Cup in 2000. 'A pitch like that is the same for everybody. It's not easy to be competitive and try to win games,' said the defender, who made 165 appearances for Chelsea in his five years with the club prior to first working with Bruce at Birmingham in 2004. 'This is the situation, though, and we have to get on with it.'