The north London side haven’t won the Premier League title since 2003-04 and haven’t reached the Champions League quarter-finals since 2010.
Arsenal have regressed at an alarming rate over the past few seasons after the Gunners finished in fifth place in the Premier League last term.
The Gunners could end up further down the Premier League table this term following another disappointing campaign under Arsene Wenger.
The French head coach is set to stand down at the end of the 2017-18 season to call time on his lengthy reign which stretches back to 1996.
Arsenal have a miserable record on the road in the Premier League this term following a return of three victories in 16 away fixtures.
The Gunners have also conceded 46 times in 34 games in the Premier League to raise questions about Wenger’s defence.
Former Manchester United captain Keane put his finger on the difference between the great Arsenal teams that he faced during his career and the current Gunners crop.
“In my time, we knew they were going to be the toughest games of the season,” Keane told ITV Sport.
“The Arsenal teams had a lot of power, pace, character, leaders and lots of quality. They were producing brilliant, winning football.
“You look at the Arsenal teams over the last few years, still a lot of pace but no characters or leaders so they are missing out on the top prizes.”
Arsenal can still qualify for next season’s Champions League if the Gunners win the Europa League.
MORE: Man United latest news
MORE: Arsenal latest news
MORE: Chelsea latest news
MORE: Liverpool latest news