The Toffees have are joint-second in the Premier League’s goalscoring charts, yet they sit down in 11th place in England’s top flight.
Part of the reason for this has been Roberto Martinez’s side’s failure to look secure at the back, and Jagielka admits that defensive issues have plagued his team’s season.
"If you look at our attacking options this season, then they have been frightening so it's probably our defensive side that has cost us," he said.
"There have been little reasons behind that and obviously we still have a young-ish squad, with a sprinkling of experience, but it is about getting the right balance.
Individually Everton’s defence looks strong. Leighton Baines and Seamus Coleman are considered two of the Premier League’s finest full-backs, Ramiro Funes Mori has had a great first campaign in England, and John Stones is regarded as one of the best young talents in the country. Jagielka himsel, has proven to be a very capable defender at the top level throughout his career...but Everton have still looked shaky.
The Toffees have conceded 36 times in 28 matches, meaning they have let in more goals than any side in the top half other than Chelsea.
Everton have shown a bit more steel in recent weeks though, and they are currently on a run where they have won five of their last six matches.