Roberto Martínez has said he is “not stupid enough” to believe Everton’s results will not determine his position as manager as he approaches the Merseyside derby with serious injury problems in defence.

The Everton captain, Phil Jagielka, and the right-back Séamus Coleman will both miss Wednesday’s visit to Liverpool with hamstring injuries. Leighton Baines, Aaron Lennon and Tom Cleverley remain doubtful. The absence of Jagielka and Coleman at Anfield could mean Callum Connolly, the 18-year-old who made his first senior appearance as a substitute against Southampton on Saturday, being handed a full debut against Jürgen Klopp’s team.

Martínez admits this week is a defining one for Everton, who face Manchester United in the FA Cup semi-final less than 72 hours after the derby. It would appear a defining week for the manager too, who has attracted growing criticism – including from a pitch invader at Goodison Park on Saturday – with Everton guaranteed to finish the season with their lowest points total at home since the introduction of three points for a win in 1981.

“Football is about results and I would never be stupid enough to look away from that,” said Martínez, who has taken responsibility for the dire return at Goodison. “From the first day I was the one who drove the expectations here, and the hunger and desire to be competing where we should be at Everton – playing attractive, competitive football and going eye-to-eye with teams. That is what we are going to do. We need our fans more than ever. This week is our opportunity to show how good we can be when we are together.”

In contrast to eight league defeats at Goodison, Everton have lost only two away games in the Premier League this season, at Arsenal and Manchester United. They have, however, won only one more game on their travels, five, and their haul of 24 away points is the seventh highest tally in the division.

Yet Martínez claimed: “Our away record is the way forward. It is quite a unique situation. A team can go through a bad spell home and away but it is rare to see a team that is so consistent away. It is Champions League form. Our home form has to mirror that as it would enable us to fight for what we want to achieve and we will assess that at the end of the season.

“Our results have not been good enough at home and I take responsibility for that. It is not a question of style. It is a case of becoming better at what we want to do.”