After 22 years under the guidance of Arsene Wenger, a new era has been opened at Emirates Stadium.
The former Gunners defender told the Daily Mail: “It may be all change but there will always be expectation.
“Unai Emery is a successful manager who is not here to finish fifth. I’m not saying they are ready for a title challenge but the top four has to be the objective.
“I’ve been impressed with Emery. He has worked his players hard in pre-season.
“Arsenal’s away form was embarrassing but they will have a better balance this year. They have a warrior in Sokratis while Lucas Torreira can bring bite to the midfield.”
Arsenal have been handed the toughest of starts to their 2018-19 Premier League campaign, as they prepare to open things up against reigning champions Manchester City.
Pep Guardiola’s record-breaking champions looked to be moving through the gears in a Community Shield victory over Chelsea, but Keown believes Arsenal can claim a notable scalp on home soil.
He added: “Unlike their rivals, Arsenal only had one player in the World Cup semi-finals. City had seven.
“When they travel to the Emirates on Sunday the likes of Kevin De Bruyne and Raheem Sterling may be unavailable.
“Arsenal will not have a better chance to beat the all-conquering champions. Do so, and they could steal a march on their rivals.”