LIVERPOOL -- Tim Howard has the strength of character to regain his form after a disappointing week, according to Everton manager Roberto Martinez.
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The U.S. international goalkeeper was at fault for two goals as the Toffees fell to a surprising 3-2 Premier League defeat at home to Crystal Palace last Sunday.
Howard has been beaten 13 times in five league matches this season, and conceded another three in Tuesday's Capital One Cup defeat at Swansea.
While the 35-year-old could not be held at fault for the bulk of those goals, Martinez acknowledged that his first-choice keeper has not always been at his best since returning from the World Cup.
Howard was outstanding for his country as they reached the last 16 in Brazil, but could still be suffering the after-effects of his efforts during the summer, according to Everton's boss.
"Any player who comes back from a World Cup needs a little bit of an adaptation period," Martinez said.
"Tim is such an experienced footballer, and we know what level he can reach.
"When you get a performance that is a little bit below those standards, it surprises you more than it would with anyone else."
#INSERT type:image caption:Tim Howard has the strength of character to regain his form after a disappointing week, according to Everton manager Roberto Martinez. END#
Howard made a string of fine saves for Everton during their 4-1 Europa League victory over Wolfsburg last Thursday, and Martinez is looking for his keeper to return to that level of form against neighbours Liverpool at Anfield on Saturday.
The manager said: "Against Wolfsburg, that was as good as I've seen Tim, not just in terms of what he did in goal, but also with his distribution. I thought he was very bright and sharp.
"Then obviously, he'll be the first one to admit that the second goal against Crystal Palace was something that we don't see in his repertoire.
"That's part of the game. Sometimes when you're defending the goal, you're going to be punished for your mistakes.
"But Tim has been working really well. I see him with a real desire to be as good as he can be, and to be a massive influence to everyone else at the club.
"In general, it's a start to the season that is normal. It's a transitional period. But I see him having the potential to have a very strong season, as he's had during the many years he's been with us."
Martinez described Everton's defeat against Palace last Sunday as "spooky" -- as they lost by the same score at home to the same team last season.
But he is hoping that history repeats itself in a more positive way in the Merseyside derby on Saturday.
The match will be played on the 15th anniversary of Everton's last Anfield victory, which came when Kevin Campbell scored the only goal of their Premier League meeting on Sept. 27, 1999.
Last season, Martinez guided the Toffees to their first away win over Manchester United since 1992, and is looking to end another barren sequence this weekend.
He said: "I said that the defeat against Crystal Palace was something spooky. The last time we beat Liverpool at Anfield was Sept. 27, so I hope that spookiness carries on into the weekend.
"The stats are there to be broken. That's something we need to make sure we embrace. We look forward to it.
"We know it's a difficult place to visit. But there are many difficult places in this league where we've gone and changed the stats and the history.
"I see it as a positive. It's something you look forward to. I'm sure we can change those stats. That's an extra bit of motivation."