Petr Cech has said Arsenal are making too many mistakes in away matches but is struggling to pinpoint the reason behind their slump on the road.
Arsenal lost 2-1 at Newcastle on Sunday, leaving them without a Premier League away point in 2018 --- the worst record in England's top four divisions.
Arsene Wenger's team are now focused on winning the Europa League to secure Champions League football next season, and Cech said it was hard to work out why they were struggling away from North London.
"It is very difficult to explain why because, until last season, we were one of the best teams in terms of the away record -- but somehow it has completely reversed this season and we don't seem to find the answer for it," the goalkeeper told the London Evening Standard.
"When you commit so many team mistakes, away or home, you get punished, and Sunday proved that.
"Of course you try to address that, but clearly the same things are happening. We don't do these mistakes -- the team mistakes -- when we play at home. Unfortunately, it has affected our results."
Arsenal led 1-0 at Newcastle thanks to Alexandre Lacazette but collapsed defensively as mistakes were made for both Newcastle goals.
"Having gone 1-0 up, we were pretty much in control. The continuation of errors for the second goal kind of sums up our season. It devalues the good things we have done," Cech said.
"It is not the first time we were 1-0 up away and we didn't get anything in the game."
The loss left Arsenal five points behind fifth-place Chelsea and only two ahead of seventh-placed Burnley as they look set for their worst league finish under Wenger.
Cech said they could not disregard the remaining league games and only focus on the Europa League, where they face Atletico Madrid in the semifinals.
"We are in the two competitions, so we need to keep switching between them and do our best," he said.
"We are in a position where we must win all our remaining games and hope it lifts us in the table. We are in a very difficult moment because everybody else has a big advantage.
"In the Europa League we have a semifinal to play, so we need to make sure we are ready."