Everton's bid to arrest an alarming run of form has been hit by an injury to goalkeeper Tim Howard ahead of Thursday's trip to Hull City in the Premier League.

Howard will be out for up to six weeks after damaging his calf in the 1-0 Boxing Day defeat by Stoke City, leaving Everton with only 24-year-old Joel Robles -- who has made only 11 top-flight starts -- as back-up.

Aside from the Spaniard, the only other goalkeepers on Everton's books are 18-year-olds Jindrich Stanek and Russell Griffiths, and manager Roberto Martinez has hinted the club may be forced to bring in reinforcements.

"That is something we are going to assess," Martinez said. "Joel had his first start in the league and that was a great way of him having an introduction.

"We've just found out about Tim so we're going to make a decision. We only have Russell and Jindrich, so we need to assess that over the next few days."

Christmas defeats against Stoke and Newcastle United have left Everton on a run of six defeats from their last eight games in all competitions and with just one victory from their last seven league matches.

The visit to Hull presents an opportunity to rectify that run, although Everton's injury problems extend beyond the goalkeeper position.

England defenders Phil Jagielka and John Stones are expected to be missing with ankle injuries, while full-back Tony Hibbert is two weeks from match fitness.

Leon Osman, another potential defensive stand-in, has a split tendon in his foot, with no return date currently scheduled, while midfielders Darron Gibson and Steven Pienaar also remain on the long-term injured list.

There is even a doubt for Thursday over the fitness of influential midfielder James McCarthy.

"At the moment, we're a little bit weak and we need to get stronger," said Martinez.

"When you don't get results, you are going to get a lot of doubts and a lot of opinions from outside. Now our focus has to be very narrow, on a positive performance and result from the Hull game."

Hull's preparations for the match have been carried out amid speculation surrounding their manager, Steve Bruce.

Bruce has been linked with a move to take over as manager of Newcastle United, with Alan Pardew expected to be named Crystal Palace manager.

Bruce, who turns 54 on Wednesday, supported Newcastle as a boy and has previously expressed regret at rejecting the chance to manage the club in 2004.

But his immediate priority is to lift his current team's morale after their defeat at Leicester City on Sunday.

The Tigers had ended a run of 10 matches without a win by beating Sunderland 3-1 on Boxing Day, but were brought back down to earth at the KC Stadium as Leicester snatched a 1-0 victory.

"They are deflated," said Bruce, whose side have won only once at home this season. "If you get beaten and deserve to, then fine. But when you don't deserve it, of course it leaves a bad taste.

"For all the good work at Sunderland, it has unravelled a bit. That is the way this league works and we have to stay with it. We have a big game on Thursday and we go again."

Bruce will be without midfielders Tom Huddlestone and Stephen Quinn, who are both suspended, but defender James Chester will return, having served a one-match ban.

Andy Robertson could also return after suffering with a knee problem, but Mohamed Diame and Michael Dawson remain sidelined.