Chelsea have suffered three defeats in their last five Premier League games and have slipped out of the top four after making an encouraging start.
Lampard is under pressure to deliver after Chelsea spent in excess of £200 million on new players last year.
But Keane believes the 42-year-old will not be given the same amount of time as Jurgen Klopp was given to rebuild his squad at Liverpool.
Keane also raised concerns over the mentality of Chelsea’s squad after Lampard publicly questioned the desire and attitude of his players in the wake of their defeat to Arsenal last month.
‘I think it’s a strange one, I think Frank always comes across well, he’s a pretty honest guy, he’s spoken about patience… I didn’t realise the world patience existed at Chelsea, particularly for managers,’ Keane told Sky Sports.
‘They’ve chopped and changed with managers who have had success there. I don’t think Frank’s going to get that much time.
‘I think there’s huge pressure this year because of the money they’ve spent, and I agree, you have to give players time to settle in, most of the signings have come from foreign countries. It takes time.
‘It’s a strange time, we’re talking negatively about where Chelsea are but if they win today they go back into the top four.
‘Last year he had a bit of free hit because he had the excuse of the transfer market [ban].
‘Now he’s spent, whatever you spent it brings added pressure, no matter who the manager is.
‘I think he’s got to keep their heads, stay strong, get that spark back into the team, try to get a settled team.
‘He’s mentioned about injured players… every team has injury problems, he’s got to get on with it.
‘The words he’s used that I’ve read recently from him where he’s questioned the desire of the team – now that is a worry.
‘The one thing I would say with Frank, if you look at Frank’s situation coming into management obviously he’s new to it in terms of having two or three seasons involved, to compare him to Klopp, remember Klopp came from Dortmund and he won big prizes over there.
‘I know that’s the name of the game. Ancelotti, Mourinho, Pep [Guardiola], you’re up against all these managers and we’re saying ‘listen, patience and time’, but these lads have got a bit of a CV behind them, they’ve won the big prizes.
‘He [Lampard] won’t get the time that Klopp got [at Liverpool].’