Roberto Martinez
Lukaku was taken from the field in the first half.

Everton manager Roberto Martinez will resist delving into the January transfer window to replace Romelu Lukaku despite the Belgian being stretchered off after picking up an ankle injury in the Merseyside derby humiliation against Liverpool.

Lukaku, who was replaced in the first half after a collision with Gareth Barry in the lead up to Steven Gerrard giving the Reds the lead in a 4-0 win, left Anfield in a cast and will be assessed to reveal the full extent of the damage.

Having sold Nikica Jelavic to Hull City and signed Lacina Traore from Monaco, the loss of Lukaku puts Everton back to square one and could force Martinez to delve into the window in order to cover for the injury stricken on loan Chelsea forward.

However, Martinez is expected to stick with his current squad despite losing a second player in as many games after Bryan Oviedo's season-ending leg-break in the FA Cup win over Stevenage.

"It's one of those situations where we've had too many accidents on a football field," Martinez said.

"The squad should be big enough when everyone is back from the little niggles. The deadline is Friday so we've got a bit of time but it's about trying to get everyone fit and back from the injuries they have."

Lukaku will join Oviedo, Darron Gibson and Arouna Kone on the side-lines for Everton, but news regarding the 20 year old's injury prognosis, which could affect his chances of playing in the 2014 World Cup is yet to be revealed.

"Rom [Lukaku] has picked up what looks a nasty injury," the Everton boss added. "We're going to assess it. At the moment he's got his ankle in a cast and it doesn't look too good.

"He just collided with Gareth Barry at the corner as the ball was delivered into the near post. It could be ankle ligaments."