Wanderers are sweating on the fitness of Zat Knight after he was stretchered off against Everton.

The Wanderers defender underwent a scan yesterday after damaging knee ligaments in Sunday’s 2-0 victory.

Initial reports suggested the injury was not as bad as first feared, but the club will know more in a week’s time when the swelling goes down.

He will definitely miss tomorrow night’s FA Cup fourth round replay at Wigan and the potential fifth round clash at Fulham on Sunday.

New signing David Wheater will continue in place of the 30-year-old, who had played every minute of every game this season, after coming on to make his Premier League debut for Bolton following his January arrival from Middlebrough.

Knight injured his knee when Blues striker Victor Anichebe fell awkwardly on his leg after making a goal-saving challenge in the first half of Sunday’s triumph.

And his absence will be a disruption Owen Coyle could have done without after his previously leaky defence’s clean sheet against the Merseysiders was their third in a row at the Reebok.

“Zat’s been outstanding for me and I think he’s played every game for me,” said the manager. “He’s been a big player for us.

“But David Wheater came in and showed his quality. He was terrific.”

Chung-Yong Lee, Martin Petrov, Ivan Klasnic, Rodrigo Moreno and Fabrice Muamba will come into Coyle’s plans for the tie with Wigan, with a fifth round showdown with Fulham at Craven Cottage on Sunday awaiting the winner.

And the Bolton boss is delighted to have more options available after being shorn of numbers over the festive period.

He said: “There will be two or three players who come into my thinking so we can keep that freshness and energy.

“There’s good players sitting there waiting to play. From having just 15 fit players in January, we’ve now got real strength in depth and quality in our squad. When you look at the boys who have missed out: Petrov, Klasnic, Chung-Yong Lee, Rodrigo Moreno and Fabrice Muamba, it’s a nice problem to have.”