Manchester City have "peaked" under Pep Guardiola, according to Dietmar Hamann, who thinks "any other manager would be in big bother" if they had failed as often on the European stage.
Guardiola's nine-year wait for success in the Champions League was extended after City suffered a shock quarter-final defeat at the hands of Lyon last season.
The Spanish boss has not won the competition since leaving Barcelona, having also fallen short at Bayern Munich, with supporters at Etihad Stadium growing increasingly impatient with each passing year.
Guardiola has delivered eight trophies during his four-year stay in Manchester, including two Premier League titles, but a lack of success in Europe's elite competition is now beginning to threaten his legacy.
Hamann has suggested that the 49-year-old is only still in the job because he played alongside City’s director of football, Txiki Begiristain, at Barcelona.
Begiristain spent seven years in the same boardroom role at Camp Nou, the last two of which saw him work closely with Guardiola, and the former Blues midfielder thinks their alliance has kept his position safe.
“If you look at their record in the Champions League, any other manager would’ve been in big bother,” Hamann told talkSPORT.
“Obviously he’s got some Barcelona history in the boardroom and maybe that’s why he’s still there.
“He didn’t reach a final with Bayern Munich or Man City – and if you look at the teams who did, they don’t have the same funds.
“It’s simply not good enough. If you look at the teams who beat them, I just wonder what has to happen for them to make a change.
“We don’t like managers getting sacked, but I think any other manager would be in big bother.”
City made it two wins from two in the current Champions League campaign by beating Marseille 2-0 at Orange Velodrome on Tuesday, but Hamann doesn't think the club will win the trophy any time soon.
The ex-Germany international, who also played for Bayern and Liverpool, believes City have gone as far as they possibly can with Guardiola, adding: "Historically, he was at Munich for three years and he improved the team, but the players were happy when he left because he was so demanding.
“I think a manager like Guardiola can’t be at a club for more than four or five years.
“He’s done that at Man City and if you see the players they bring in, there is no continuity and I don’t see them improving enough with the money they’ve spent.
“I think they’ve peaked under Guardiola, I don’t see them winning the Premier League or the Champions League in the next few years.”