The Champions League title would be "the pinnacle" for Manchester City and a greater prize than successive Premier League crowns, according to Paul Dickov.
Despite the vast investment in the playing squad since Sheikh Mansour's takeover 10 years ago, City are yet to make much of an impression in Europe.
City reached the semi-finals in the 2015-16 Champions League but lost to Real Madrid, who have won the tournament in each of the last three seasons.
Nobody has been able to retain the Premier League title since the 2008-09 season when City's rivals United wrapped up their third straight success, while three different clubs have lifted the trophy since 2015.
But asked whether domestic dominance or a first European crown would be more important to the club, Dickov said the Champions League - which Pep Guardiola won twice at Barcelona - has the edge.
"I would take both," Dickov, who played for City between 1996 and 2002, told Omnisport.
"Back-to-back Premier Leagues, it is so difficult to do, but I think if you look at the Champions League - where I feel we were really close last year and unlucky in the Liverpool games last season - the Champions League has to be the pinnacle.
"Look what they did last season - every competition they took very seriously - Pep Guardiola, the way he is, he's a serial winner and he will want to win in every competition he competes in."
City smashed a series of Premier League records as they romped to the title last term, but this season Liverpool and Chelsea both appear to be offering stronger competition.
Liverpool host City on Sunday, with both sides unbeaten in the league so far this term, and Dickov feels that while his old club will have to fight for the title, they will come out on top.
"I do think it will be close but I think the gap that Manchester City had last year away from everybody else, this season especially will be too much to make up," Dickov added.
"They were by far way ahead of everyone else last year, if Man City were up there and everybody else was back down here I think that gap might close a little bit, but I think its too much for the other teams to compete."
